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New and Noteworthy Information—September 2013
A recent case–control study provides further evidence against the Zamboni hypothesis that chronic cerebrospinal venous insufficiency is involved with multiple sclerosis (MS), researchers reported August 14 in PLOS One. The researchers randomly selected 100 patients with MS between ages 18 and 65 and 100 controls with no known history of MS or other neurologic condition. All participants underwent ultrasound imaging of the veins of the neck and the deep cerebral veins, as well as MRI of the neck veins and brain. The investigators found no evidence of reflux, stenosis, or blockage in the internal jugular veins or vertebral veins in any study participant and no evidence of reflux or cessation of flow in the deep cerebral veins in any subject.
Breastfeeding may reduce a woman’s risk of Alzheimer’s disease, according to research published online ahead of print July 23 in the Journal of Alzheimer’s Disease. Investigators collected reproductive history data from and conducted Alzheimer’s disease diagnostic interviews with a cohort of elderly British women. Analysis using Cox proportional-hazard models indicated that longer breastfeeding duration corresponded to reduced risk of Alzheimer’s disease. Women who breastfed had lower risk of Alzheimer’s disease than women who did not breastfeed. Breastfeeding practices are an important modifier of cumulative endogenous hormone exposure for mothers, according to the researchers. Future studies should consider how reproductive history leads to variation in endogenous hormone exposure and how this variation may influence the relationship between hormones and Alzheimer’s disease, the investigators concluded.
Among older adults, anemia may be associated with an increased risk of dementia, according to a study published August 6 in Neurology. Researchers studied 2,552 older adults (mean age, 76) participating in the Health, Aging, and Body Composition study and who were free of dementia at baseline. Of the total population, 392 participants had anemia at baseline. Over 11 years of follow-up, 455 participants developed dementia. An unadjusted analysis indicated that subjects with baseline anemia had an increased risk of dementia (23% vs 17%) compared with subjects without anemia. The association remained significant after adjusting for demographics, APOE ε4, baseline Modified Mini-Mental State score, comorbidities, and renal function. Additional adjustment for other anemia measures, erythropoietin, and C-reactive protein did not affect the results significantly.
The FDA has approved Trokendi XR, a once-daily extended release formulation of topiramate for the treatment of epilepsy. The agency granted a waiver for certain pediatric study requirements and a deferral for the submission of postmarketing pediatric pharmacokinetic assessments. Trokendi XR is indicated for initial monotherapy in patients ages 10 and older with partial onset or primary generalized tonic–clonic seizures. The drug also is approved as adjunctive therapy in patients ages 6 and older with partial onset or primary generalized tonic–clonic seizures, and as adjunctive therapy in patients ages 6 and older with seizures associated with Lennox–Gastaut syndrome. The product will be available in 25-, 50-, 100- and 200-mg extended-release capsules. Supernus Pharmaceuticals (Rockville, Maryland) expects to launch the product in September 2013.
The FDA has approved scored tablet and oral suspension formulations of ONFI (clobazam) CIV. ONFI is an oral antiepileptic drug of the benzodiazepine class (ie, a 1,5 benzodiazepine). The agency originally approved ONFI in 2011 as a prescription medication to treat seizures associated with Lennox–Gastaut syndrome in adults and children age 2 or older. The new oval-shaped ONFI scored tablets (10 mg and 20 mg) will replace the round, nonscored tablets and are similar in size. The new tablets contain the same ingredients as the round tablet, and the score allows patients or their caregivers to split the tablets in half. ONFI oral suspension (2.5 mg/mL) has a berry flavor. ONFI, manufactured by Lundbeck (Deerfield, Illinois), will no longer be available in a 5-mg tablet.
An incomplete circle of Willis may be more common in patients with migraine with aura than in the general population, according to research published July 26 in PLOS One. Investigators enrolled 56 migraineurs with aura, 61 migraineurs without aura, and 53 controls in an observational study. The researchers performed magnetic resonance angiography to examine subjects’ circle of Willis anatomy and measured cerebral blood flow with arterial spin–labeled perfusion MRI. An incomplete circle of Willis was significantly more common in migraineurs with aura, compared with controls (73% vs 51%). A similar trend was observed among migraineurs without aura (67% vs 51%). Compared with subjects with a complete circle of Willis, subjects with an incomplete circle had greater asymmetry in hemispheric cerebral blood flow.
Some patients with chronic pain diagnosed as fibromyalgia may have unrecognized small-fiber polyneuropathy (SFPN), according to research published online ahead of print June 7 in Pain. Investigators analyzed symptoms associated with SFPN, neurologic examinations, and pathologic and physiologic markers in 27 patients with fibromyalgia and 30 matched normal controls. Study instruments included the Michigan Neuropathy Screening Instrument (MNSI), the Utah Early Neuropathy Scale (UENS), distal-leg neurodiagnostic skin biopsies, and autonomic-function testing (AFT). Approximately 41% of skin biopsies from subjects with fibromyalgia supported a diagnosis of SFPN, compared with 3% of biopsies from control subjects. MNSI and UENS scores were higher in patients with fibromyalgia than in control subjects. Abnormal AFTs were prevalent among patients with fibromyalgia, suggesting that fibromyalgia-associated SFPN is primarily somatic, said the researchers.
High glucose levels may be a risk factor for dementia, even among persons without diabetes, according to a study published August 8 in the New England Journal of Medicine. Researchers examined 35,264 clinical measurements of glucose levels and 10,208 measurements of glycated hemoglobin levels from 2,067 participants (1,228 women) without dementia. Participants’ mean age at baseline was 76. Of the total population, 232 participants had diabetes. During a median follow-up of 6.8 years, 524 participants developed dementia (74 with diabetes). Among participants without diabetes, higher average glucose levels within the preceding five years were related to an increased risk of dementia. A glucose level of 115 mg/dL, compared with 100 mg/dL, was associated with an adjusted hazard ratio for dementia of 1.18.
A majority of Alzheimer’s disease investigators favor disclosing amyloid imaging results to participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), according to a survey published online ahead of print August 21 in Neurology. Shortly before the FDA approved the amyloid-binding radiotracer florbetapir, all ADNI investigators and personnel were asked to complete an anonymous online survey that contained fixed-choice and free-text questions. Although ADNI participants often requested amyloid imaging results, the majority of ADNI investigators (approximately 90%) did not return amyloid imaging results to the participants. Most investigators reported that if the FDA approved florbetapir, they would support the return of amyloid imaging results to participants with mild cognitive impairment and normal cognition, however. ADNI investigators emphasized the need for guidance on how to provide these results to participants.
A sudden decrease of testosterone may induce nigrostriatal pathologies in mice through a decrease in glial-derived neurotrophic factor (GDNF) mediated by inducible nitric-oxide synthase (iNOS), investigators reported in the July 19 Journal of Biological Chemistry. Levels of iNOS, glial markers, and α-synuclein were higher in the nigra of castrated male mice than in normal male mice. After castration, the level of GDNF markedly decreased in the nigra of male mice, however. Subcutaneous implantation of 5 α-dihydrotestosterone pellets reversed nigrostriatal pathologies in castrated male mice, suggesting that the male sex hormone plays a role in castration-induced nigrostriatal pathology. Castrated young male mice may be used as a simple, toxin-free, and nontransgenic animal model to study Parkinson’s disease-related nigrostriatal pathologies, thus facilitating the screening of drugs against Parkinson’s disease, said the researchers.
IV thrombolysis within 90 minutes may be associated with excellent outcomes in patients with moderate and mild stroke, according to research published online ahead of print August 22 in Stroke. Investigators prospectively collected data for consecutive ischemic stroke patients who received IV thrombolysis at 10 European stroke centers. Logistic regression analysis suggested that shorter onset-to-treatment time was significantly associated with excellent outcome. Patients with onset-to-treatment time of 90 minutes or less had lower frequency of intracranial hemorrhage. After adjusting for age, sex, admission glucose level, and year of treatment, the researchers found that onset-to-treatment time of 90 minutes or less was associated with excellent outcome in patients with NIH Stroke Scale (NIHSS) score from 7 to 12, but not in patients with baseline NIHSS score greater than 12 and baseline NIHSS 0 to 6.
A neo-substrate approach involving the adenosine triphosphate (ATP) analog kinetin triphosphate (KTP) can increase the activity of Parkinson’s disease–related mutant PINK1G309D and PINK1WT, according to research published on August 15 in Cell. Investigators found that the normal and mutated versions of PINK1 bind to KTP. The application of KTP precursor kinetin to cells resulted in biologically significant increases in PINK1 activity, which were manifest as higher levels of Parkin recruitment to depolarized mitochondria, reduced mitochondrial motility in axons, and lower levels of apoptosis. Kinetin could treat patients with a known PINK1 mutation and also slow disease progression in patients without a family history of the disease, said the researchers. The search for neo-substrates for kinases could provide a novel way of regulating kinase activity, they concluded.
The effect of copper on brain amyloid-β homeostasis depends on whether it is accumulated in the capillaries or in the parenchyma, researchers reported online ahead of print August 19 in Proceedings of the National Academy of Sciences. In aging mice, the accumulation of copper in brain capillaries was associated with its reduction in low-density lipoprotein receptor–related protein 1 (LRP1) and higher brain amyloid-β levels. In human brain endothelial cells, normal labile levels of copper caused the downregulation of LRP1 by inducing nitrotyrosination and subsequent proteosomal-dependent degradation, partly because of interactions between copper, cellular prion protein, and LRP1. In APPsw/0 mice, copper downregulated LRP1 in brain capillaries and increased amyloid-b production and neuroinflammation. The effect resulted from the accumulation of copper in brain capillaries and in the parenchyma.
—Erik Greb
Senior Associate Editor
A recent case–control study provides further evidence against the Zamboni hypothesis that chronic cerebrospinal venous insufficiency is involved with multiple sclerosis (MS), researchers reported August 14 in PLOS One. The researchers randomly selected 100 patients with MS between ages 18 and 65 and 100 controls with no known history of MS or other neurologic condition. All participants underwent ultrasound imaging of the veins of the neck and the deep cerebral veins, as well as MRI of the neck veins and brain. The investigators found no evidence of reflux, stenosis, or blockage in the internal jugular veins or vertebral veins in any study participant and no evidence of reflux or cessation of flow in the deep cerebral veins in any subject.
Breastfeeding may reduce a woman’s risk of Alzheimer’s disease, according to research published online ahead of print July 23 in the Journal of Alzheimer’s Disease. Investigators collected reproductive history data from and conducted Alzheimer’s disease diagnostic interviews with a cohort of elderly British women. Analysis using Cox proportional-hazard models indicated that longer breastfeeding duration corresponded to reduced risk of Alzheimer’s disease. Women who breastfed had lower risk of Alzheimer’s disease than women who did not breastfeed. Breastfeeding practices are an important modifier of cumulative endogenous hormone exposure for mothers, according to the researchers. Future studies should consider how reproductive history leads to variation in endogenous hormone exposure and how this variation may influence the relationship between hormones and Alzheimer’s disease, the investigators concluded.
Among older adults, anemia may be associated with an increased risk of dementia, according to a study published August 6 in Neurology. Researchers studied 2,552 older adults (mean age, 76) participating in the Health, Aging, and Body Composition study and who were free of dementia at baseline. Of the total population, 392 participants had anemia at baseline. Over 11 years of follow-up, 455 participants developed dementia. An unadjusted analysis indicated that subjects with baseline anemia had an increased risk of dementia (23% vs 17%) compared with subjects without anemia. The association remained significant after adjusting for demographics, APOE ε4, baseline Modified Mini-Mental State score, comorbidities, and renal function. Additional adjustment for other anemia measures, erythropoietin, and C-reactive protein did not affect the results significantly.
The FDA has approved Trokendi XR, a once-daily extended release formulation of topiramate for the treatment of epilepsy. The agency granted a waiver for certain pediatric study requirements and a deferral for the submission of postmarketing pediatric pharmacokinetic assessments. Trokendi XR is indicated for initial monotherapy in patients ages 10 and older with partial onset or primary generalized tonic–clonic seizures. The drug also is approved as adjunctive therapy in patients ages 6 and older with partial onset or primary generalized tonic–clonic seizures, and as adjunctive therapy in patients ages 6 and older with seizures associated with Lennox–Gastaut syndrome. The product will be available in 25-, 50-, 100- and 200-mg extended-release capsules. Supernus Pharmaceuticals (Rockville, Maryland) expects to launch the product in September 2013.
The FDA has approved scored tablet and oral suspension formulations of ONFI (clobazam) CIV. ONFI is an oral antiepileptic drug of the benzodiazepine class (ie, a 1,5 benzodiazepine). The agency originally approved ONFI in 2011 as a prescription medication to treat seizures associated with Lennox–Gastaut syndrome in adults and children age 2 or older. The new oval-shaped ONFI scored tablets (10 mg and 20 mg) will replace the round, nonscored tablets and are similar in size. The new tablets contain the same ingredients as the round tablet, and the score allows patients or their caregivers to split the tablets in half. ONFI oral suspension (2.5 mg/mL) has a berry flavor. ONFI, manufactured by Lundbeck (Deerfield, Illinois), will no longer be available in a 5-mg tablet.
An incomplete circle of Willis may be more common in patients with migraine with aura than in the general population, according to research published July 26 in PLOS One. Investigators enrolled 56 migraineurs with aura, 61 migraineurs without aura, and 53 controls in an observational study. The researchers performed magnetic resonance angiography to examine subjects’ circle of Willis anatomy and measured cerebral blood flow with arterial spin–labeled perfusion MRI. An incomplete circle of Willis was significantly more common in migraineurs with aura, compared with controls (73% vs 51%). A similar trend was observed among migraineurs without aura (67% vs 51%). Compared with subjects with a complete circle of Willis, subjects with an incomplete circle had greater asymmetry in hemispheric cerebral blood flow.
Some patients with chronic pain diagnosed as fibromyalgia may have unrecognized small-fiber polyneuropathy (SFPN), according to research published online ahead of print June 7 in Pain. Investigators analyzed symptoms associated with SFPN, neurologic examinations, and pathologic and physiologic markers in 27 patients with fibromyalgia and 30 matched normal controls. Study instruments included the Michigan Neuropathy Screening Instrument (MNSI), the Utah Early Neuropathy Scale (UENS), distal-leg neurodiagnostic skin biopsies, and autonomic-function testing (AFT). Approximately 41% of skin biopsies from subjects with fibromyalgia supported a diagnosis of SFPN, compared with 3% of biopsies from control subjects. MNSI and UENS scores were higher in patients with fibromyalgia than in control subjects. Abnormal AFTs were prevalent among patients with fibromyalgia, suggesting that fibromyalgia-associated SFPN is primarily somatic, said the researchers.
High glucose levels may be a risk factor for dementia, even among persons without diabetes, according to a study published August 8 in the New England Journal of Medicine. Researchers examined 35,264 clinical measurements of glucose levels and 10,208 measurements of glycated hemoglobin levels from 2,067 participants (1,228 women) without dementia. Participants’ mean age at baseline was 76. Of the total population, 232 participants had diabetes. During a median follow-up of 6.8 years, 524 participants developed dementia (74 with diabetes). Among participants without diabetes, higher average glucose levels within the preceding five years were related to an increased risk of dementia. A glucose level of 115 mg/dL, compared with 100 mg/dL, was associated with an adjusted hazard ratio for dementia of 1.18.
A majority of Alzheimer’s disease investigators favor disclosing amyloid imaging results to participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), according to a survey published online ahead of print August 21 in Neurology. Shortly before the FDA approved the amyloid-binding radiotracer florbetapir, all ADNI investigators and personnel were asked to complete an anonymous online survey that contained fixed-choice and free-text questions. Although ADNI participants often requested amyloid imaging results, the majority of ADNI investigators (approximately 90%) did not return amyloid imaging results to the participants. Most investigators reported that if the FDA approved florbetapir, they would support the return of amyloid imaging results to participants with mild cognitive impairment and normal cognition, however. ADNI investigators emphasized the need for guidance on how to provide these results to participants.
A sudden decrease of testosterone may induce nigrostriatal pathologies in mice through a decrease in glial-derived neurotrophic factor (GDNF) mediated by inducible nitric-oxide synthase (iNOS), investigators reported in the July 19 Journal of Biological Chemistry. Levels of iNOS, glial markers, and α-synuclein were higher in the nigra of castrated male mice than in normal male mice. After castration, the level of GDNF markedly decreased in the nigra of male mice, however. Subcutaneous implantation of 5 α-dihydrotestosterone pellets reversed nigrostriatal pathologies in castrated male mice, suggesting that the male sex hormone plays a role in castration-induced nigrostriatal pathology. Castrated young male mice may be used as a simple, toxin-free, and nontransgenic animal model to study Parkinson’s disease-related nigrostriatal pathologies, thus facilitating the screening of drugs against Parkinson’s disease, said the researchers.
IV thrombolysis within 90 minutes may be associated with excellent outcomes in patients with moderate and mild stroke, according to research published online ahead of print August 22 in Stroke. Investigators prospectively collected data for consecutive ischemic stroke patients who received IV thrombolysis at 10 European stroke centers. Logistic regression analysis suggested that shorter onset-to-treatment time was significantly associated with excellent outcome. Patients with onset-to-treatment time of 90 minutes or less had lower frequency of intracranial hemorrhage. After adjusting for age, sex, admission glucose level, and year of treatment, the researchers found that onset-to-treatment time of 90 minutes or less was associated with excellent outcome in patients with NIH Stroke Scale (NIHSS) score from 7 to 12, but not in patients with baseline NIHSS score greater than 12 and baseline NIHSS 0 to 6.
A neo-substrate approach involving the adenosine triphosphate (ATP) analog kinetin triphosphate (KTP) can increase the activity of Parkinson’s disease–related mutant PINK1G309D and PINK1WT, according to research published on August 15 in Cell. Investigators found that the normal and mutated versions of PINK1 bind to KTP. The application of KTP precursor kinetin to cells resulted in biologically significant increases in PINK1 activity, which were manifest as higher levels of Parkin recruitment to depolarized mitochondria, reduced mitochondrial motility in axons, and lower levels of apoptosis. Kinetin could treat patients with a known PINK1 mutation and also slow disease progression in patients without a family history of the disease, said the researchers. The search for neo-substrates for kinases could provide a novel way of regulating kinase activity, they concluded.
The effect of copper on brain amyloid-β homeostasis depends on whether it is accumulated in the capillaries or in the parenchyma, researchers reported online ahead of print August 19 in Proceedings of the National Academy of Sciences. In aging mice, the accumulation of copper in brain capillaries was associated with its reduction in low-density lipoprotein receptor–related protein 1 (LRP1) and higher brain amyloid-β levels. In human brain endothelial cells, normal labile levels of copper caused the downregulation of LRP1 by inducing nitrotyrosination and subsequent proteosomal-dependent degradation, partly because of interactions between copper, cellular prion protein, and LRP1. In APPsw/0 mice, copper downregulated LRP1 in brain capillaries and increased amyloid-b production and neuroinflammation. The effect resulted from the accumulation of copper in brain capillaries and in the parenchyma.
—Erik Greb
Senior Associate Editor
A recent case–control study provides further evidence against the Zamboni hypothesis that chronic cerebrospinal venous insufficiency is involved with multiple sclerosis (MS), researchers reported August 14 in PLOS One. The researchers randomly selected 100 patients with MS between ages 18 and 65 and 100 controls with no known history of MS or other neurologic condition. All participants underwent ultrasound imaging of the veins of the neck and the deep cerebral veins, as well as MRI of the neck veins and brain. The investigators found no evidence of reflux, stenosis, or blockage in the internal jugular veins or vertebral veins in any study participant and no evidence of reflux or cessation of flow in the deep cerebral veins in any subject.
Breastfeeding may reduce a woman’s risk of Alzheimer’s disease, according to research published online ahead of print July 23 in the Journal of Alzheimer’s Disease. Investigators collected reproductive history data from and conducted Alzheimer’s disease diagnostic interviews with a cohort of elderly British women. Analysis using Cox proportional-hazard models indicated that longer breastfeeding duration corresponded to reduced risk of Alzheimer’s disease. Women who breastfed had lower risk of Alzheimer’s disease than women who did not breastfeed. Breastfeeding practices are an important modifier of cumulative endogenous hormone exposure for mothers, according to the researchers. Future studies should consider how reproductive history leads to variation in endogenous hormone exposure and how this variation may influence the relationship between hormones and Alzheimer’s disease, the investigators concluded.
Among older adults, anemia may be associated with an increased risk of dementia, according to a study published August 6 in Neurology. Researchers studied 2,552 older adults (mean age, 76) participating in the Health, Aging, and Body Composition study and who were free of dementia at baseline. Of the total population, 392 participants had anemia at baseline. Over 11 years of follow-up, 455 participants developed dementia. An unadjusted analysis indicated that subjects with baseline anemia had an increased risk of dementia (23% vs 17%) compared with subjects without anemia. The association remained significant after adjusting for demographics, APOE ε4, baseline Modified Mini-Mental State score, comorbidities, and renal function. Additional adjustment for other anemia measures, erythropoietin, and C-reactive protein did not affect the results significantly.
The FDA has approved Trokendi XR, a once-daily extended release formulation of topiramate for the treatment of epilepsy. The agency granted a waiver for certain pediatric study requirements and a deferral for the submission of postmarketing pediatric pharmacokinetic assessments. Trokendi XR is indicated for initial monotherapy in patients ages 10 and older with partial onset or primary generalized tonic–clonic seizures. The drug also is approved as adjunctive therapy in patients ages 6 and older with partial onset or primary generalized tonic–clonic seizures, and as adjunctive therapy in patients ages 6 and older with seizures associated with Lennox–Gastaut syndrome. The product will be available in 25-, 50-, 100- and 200-mg extended-release capsules. Supernus Pharmaceuticals (Rockville, Maryland) expects to launch the product in September 2013.
The FDA has approved scored tablet and oral suspension formulations of ONFI (clobazam) CIV. ONFI is an oral antiepileptic drug of the benzodiazepine class (ie, a 1,5 benzodiazepine). The agency originally approved ONFI in 2011 as a prescription medication to treat seizures associated with Lennox–Gastaut syndrome in adults and children age 2 or older. The new oval-shaped ONFI scored tablets (10 mg and 20 mg) will replace the round, nonscored tablets and are similar in size. The new tablets contain the same ingredients as the round tablet, and the score allows patients or their caregivers to split the tablets in half. ONFI oral suspension (2.5 mg/mL) has a berry flavor. ONFI, manufactured by Lundbeck (Deerfield, Illinois), will no longer be available in a 5-mg tablet.
An incomplete circle of Willis may be more common in patients with migraine with aura than in the general population, according to research published July 26 in PLOS One. Investigators enrolled 56 migraineurs with aura, 61 migraineurs without aura, and 53 controls in an observational study. The researchers performed magnetic resonance angiography to examine subjects’ circle of Willis anatomy and measured cerebral blood flow with arterial spin–labeled perfusion MRI. An incomplete circle of Willis was significantly more common in migraineurs with aura, compared with controls (73% vs 51%). A similar trend was observed among migraineurs without aura (67% vs 51%). Compared with subjects with a complete circle of Willis, subjects with an incomplete circle had greater asymmetry in hemispheric cerebral blood flow.
Some patients with chronic pain diagnosed as fibromyalgia may have unrecognized small-fiber polyneuropathy (SFPN), according to research published online ahead of print June 7 in Pain. Investigators analyzed symptoms associated with SFPN, neurologic examinations, and pathologic and physiologic markers in 27 patients with fibromyalgia and 30 matched normal controls. Study instruments included the Michigan Neuropathy Screening Instrument (MNSI), the Utah Early Neuropathy Scale (UENS), distal-leg neurodiagnostic skin biopsies, and autonomic-function testing (AFT). Approximately 41% of skin biopsies from subjects with fibromyalgia supported a diagnosis of SFPN, compared with 3% of biopsies from control subjects. MNSI and UENS scores were higher in patients with fibromyalgia than in control subjects. Abnormal AFTs were prevalent among patients with fibromyalgia, suggesting that fibromyalgia-associated SFPN is primarily somatic, said the researchers.
High glucose levels may be a risk factor for dementia, even among persons without diabetes, according to a study published August 8 in the New England Journal of Medicine. Researchers examined 35,264 clinical measurements of glucose levels and 10,208 measurements of glycated hemoglobin levels from 2,067 participants (1,228 women) without dementia. Participants’ mean age at baseline was 76. Of the total population, 232 participants had diabetes. During a median follow-up of 6.8 years, 524 participants developed dementia (74 with diabetes). Among participants without diabetes, higher average glucose levels within the preceding five years were related to an increased risk of dementia. A glucose level of 115 mg/dL, compared with 100 mg/dL, was associated with an adjusted hazard ratio for dementia of 1.18.
A majority of Alzheimer’s disease investigators favor disclosing amyloid imaging results to participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI), according to a survey published online ahead of print August 21 in Neurology. Shortly before the FDA approved the amyloid-binding radiotracer florbetapir, all ADNI investigators and personnel were asked to complete an anonymous online survey that contained fixed-choice and free-text questions. Although ADNI participants often requested amyloid imaging results, the majority of ADNI investigators (approximately 90%) did not return amyloid imaging results to the participants. Most investigators reported that if the FDA approved florbetapir, they would support the return of amyloid imaging results to participants with mild cognitive impairment and normal cognition, however. ADNI investigators emphasized the need for guidance on how to provide these results to participants.
A sudden decrease of testosterone may induce nigrostriatal pathologies in mice through a decrease in glial-derived neurotrophic factor (GDNF) mediated by inducible nitric-oxide synthase (iNOS), investigators reported in the July 19 Journal of Biological Chemistry. Levels of iNOS, glial markers, and α-synuclein were higher in the nigra of castrated male mice than in normal male mice. After castration, the level of GDNF markedly decreased in the nigra of male mice, however. Subcutaneous implantation of 5 α-dihydrotestosterone pellets reversed nigrostriatal pathologies in castrated male mice, suggesting that the male sex hormone plays a role in castration-induced nigrostriatal pathology. Castrated young male mice may be used as a simple, toxin-free, and nontransgenic animal model to study Parkinson’s disease-related nigrostriatal pathologies, thus facilitating the screening of drugs against Parkinson’s disease, said the researchers.
IV thrombolysis within 90 minutes may be associated with excellent outcomes in patients with moderate and mild stroke, according to research published online ahead of print August 22 in Stroke. Investigators prospectively collected data for consecutive ischemic stroke patients who received IV thrombolysis at 10 European stroke centers. Logistic regression analysis suggested that shorter onset-to-treatment time was significantly associated with excellent outcome. Patients with onset-to-treatment time of 90 minutes or less had lower frequency of intracranial hemorrhage. After adjusting for age, sex, admission glucose level, and year of treatment, the researchers found that onset-to-treatment time of 90 minutes or less was associated with excellent outcome in patients with NIH Stroke Scale (NIHSS) score from 7 to 12, but not in patients with baseline NIHSS score greater than 12 and baseline NIHSS 0 to 6.
A neo-substrate approach involving the adenosine triphosphate (ATP) analog kinetin triphosphate (KTP) can increase the activity of Parkinson’s disease–related mutant PINK1G309D and PINK1WT, according to research published on August 15 in Cell. Investigators found that the normal and mutated versions of PINK1 bind to KTP. The application of KTP precursor kinetin to cells resulted in biologically significant increases in PINK1 activity, which were manifest as higher levels of Parkin recruitment to depolarized mitochondria, reduced mitochondrial motility in axons, and lower levels of apoptosis. Kinetin could treat patients with a known PINK1 mutation and also slow disease progression in patients without a family history of the disease, said the researchers. The search for neo-substrates for kinases could provide a novel way of regulating kinase activity, they concluded.
The effect of copper on brain amyloid-β homeostasis depends on whether it is accumulated in the capillaries or in the parenchyma, researchers reported online ahead of print August 19 in Proceedings of the National Academy of Sciences. In aging mice, the accumulation of copper in brain capillaries was associated with its reduction in low-density lipoprotein receptor–related protein 1 (LRP1) and higher brain amyloid-β levels. In human brain endothelial cells, normal labile levels of copper caused the downregulation of LRP1 by inducing nitrotyrosination and subsequent proteosomal-dependent degradation, partly because of interactions between copper, cellular prion protein, and LRP1. In APPsw/0 mice, copper downregulated LRP1 in brain capillaries and increased amyloid-b production and neuroinflammation. The effect resulted from the accumulation of copper in brain capillaries and in the parenchyma.
—Erik Greb
Senior Associate Editor
Neurogenic thoracic outlet syndrome: An often overlooked but treatable condition
Medical Training Programs Adapt to Duty-Hour Changes
A new study that showed no long-term decrease in patient outcomes after landmark 2003 reforms could portend good news for the latest duty-hour regulations implemented in 2011.
The Journal of General Internal Medicine report, “Teaching Hospital Five-Year Mortality Trends in the Wake of Duty Hour Reforms,” found that the 2003 changes were associated with “no significant change in mortality in the early years after implementation, and with a trend toward improved mortality among medical patients in the fourth and fifth years.” One of the authors says it’s not evident whether the improved outcomes are because of the reforms.
“We don’t think it’s an effect of work-hour reforms itself, but more likely a marker that teaching hospitals are staying ahead of the curve in general,” says Patrick Romano, MD, MPH, FACP, FAAP, a professor of medicine and pediatrics at the University of California at Davis School of Medicine in Sacramento.
Dr. Romano, who along with colleagues has been studying duty-hour reforms for years, says the new research shows that teaching hospitals were able to adapt over the long term to staffing rules. Researchers are now curious how health care will adapt to the more restrictive 2011 changes promulgated by the Accreditation Council for Graduate Medical Education (ACGME), which mostly limits first-year residents to a maximum 16-hour shift and older residents to 24 hours.
“Even though there were more handoffs [caused by the 2003 reforms], even though there were more opportunities for error due to handoffs, teaching hospitals were able to update,” Dr. Romano says. “Maybe that’s optimistic for 2011.
“Is the glass half full or half empty?”
Visit our website for more information on duty hours.
A new study that showed no long-term decrease in patient outcomes after landmark 2003 reforms could portend good news for the latest duty-hour regulations implemented in 2011.
The Journal of General Internal Medicine report, “Teaching Hospital Five-Year Mortality Trends in the Wake of Duty Hour Reforms,” found that the 2003 changes were associated with “no significant change in mortality in the early years after implementation, and with a trend toward improved mortality among medical patients in the fourth and fifth years.” One of the authors says it’s not evident whether the improved outcomes are because of the reforms.
“We don’t think it’s an effect of work-hour reforms itself, but more likely a marker that teaching hospitals are staying ahead of the curve in general,” says Patrick Romano, MD, MPH, FACP, FAAP, a professor of medicine and pediatrics at the University of California at Davis School of Medicine in Sacramento.
Dr. Romano, who along with colleagues has been studying duty-hour reforms for years, says the new research shows that teaching hospitals were able to adapt over the long term to staffing rules. Researchers are now curious how health care will adapt to the more restrictive 2011 changes promulgated by the Accreditation Council for Graduate Medical Education (ACGME), which mostly limits first-year residents to a maximum 16-hour shift and older residents to 24 hours.
“Even though there were more handoffs [caused by the 2003 reforms], even though there were more opportunities for error due to handoffs, teaching hospitals were able to update,” Dr. Romano says. “Maybe that’s optimistic for 2011.
“Is the glass half full or half empty?”
Visit our website for more information on duty hours.
A new study that showed no long-term decrease in patient outcomes after landmark 2003 reforms could portend good news for the latest duty-hour regulations implemented in 2011.
The Journal of General Internal Medicine report, “Teaching Hospital Five-Year Mortality Trends in the Wake of Duty Hour Reforms,” found that the 2003 changes were associated with “no significant change in mortality in the early years after implementation, and with a trend toward improved mortality among medical patients in the fourth and fifth years.” One of the authors says it’s not evident whether the improved outcomes are because of the reforms.
“We don’t think it’s an effect of work-hour reforms itself, but more likely a marker that teaching hospitals are staying ahead of the curve in general,” says Patrick Romano, MD, MPH, FACP, FAAP, a professor of medicine and pediatrics at the University of California at Davis School of Medicine in Sacramento.
Dr. Romano, who along with colleagues has been studying duty-hour reforms for years, says the new research shows that teaching hospitals were able to adapt over the long term to staffing rules. Researchers are now curious how health care will adapt to the more restrictive 2011 changes promulgated by the Accreditation Council for Graduate Medical Education (ACGME), which mostly limits first-year residents to a maximum 16-hour shift and older residents to 24 hours.
“Even though there were more handoffs [caused by the 2003 reforms], even though there were more opportunities for error due to handoffs, teaching hospitals were able to update,” Dr. Romano says. “Maybe that’s optimistic for 2011.
“Is the glass half full or half empty?”
Visit our website for more information on duty hours.
Steroids May Increase Venous Thromboembolism Risk
Clinical question: Is exogenous glucocorticoid administration associated with an increased risk of VTE?
Background: Endogenous hypercortisolism is linked to increased VTE rates, and pathophysiologic data exist to suggest glucocorticoids increase clotting, but few studies have measured the clinical link between glucocorticoid administration and VTE events.
Study design: Case-control study.
Setting: Denmark.
Synopsis: The authors analyzed Danish national registries, which include information on diagnoses and prescriptions. The study selection period was Jan. 1, 2005, to Dec. 31, 2011. During this period, 38,675 cases of VTE (both DVT and pulmonary embolism) were identified in the population of Denmark. These cases were matched with 387,650 controls. Three routes of glucocorticoid use were studied: systemic (oral and intravenous), inhaled, and intestinal-acting. Cases were classified as present (within 90 days of VTE event), recent (within 91 to 365 days), or former (more than 365 days prior) users of glucocorticoids. Categories were also created for new versus continuous users.
Glucocorticoid use was associated with a significant increase in VTE occurrence. The strongest link was in new and recent users, and the effect diminished over time. Key limitations of the study included its reliance on registry data, as well as the fact that cases had more comorbid conditions than controls (e.g. recent infection, chronic illnesses).
Bottom line: Recipients of glucocorticoids had an increased risk of VTE; the effect was strongest in new and recent users.
Citation: Johannesdottir SA, Horvath-Puho E, Dekkers OM, et al. Use of glucocorticoids and risk of venous thromboembolism. JAMA Intern Med. 2013;173(9):743-752.
Visit our website for more physician reviews of recent HM-relevant literature.
Clinical question: Is exogenous glucocorticoid administration associated with an increased risk of VTE?
Background: Endogenous hypercortisolism is linked to increased VTE rates, and pathophysiologic data exist to suggest glucocorticoids increase clotting, but few studies have measured the clinical link between glucocorticoid administration and VTE events.
Study design: Case-control study.
Setting: Denmark.
Synopsis: The authors analyzed Danish national registries, which include information on diagnoses and prescriptions. The study selection period was Jan. 1, 2005, to Dec. 31, 2011. During this period, 38,675 cases of VTE (both DVT and pulmonary embolism) were identified in the population of Denmark. These cases were matched with 387,650 controls. Three routes of glucocorticoid use were studied: systemic (oral and intravenous), inhaled, and intestinal-acting. Cases were classified as present (within 90 days of VTE event), recent (within 91 to 365 days), or former (more than 365 days prior) users of glucocorticoids. Categories were also created for new versus continuous users.
Glucocorticoid use was associated with a significant increase in VTE occurrence. The strongest link was in new and recent users, and the effect diminished over time. Key limitations of the study included its reliance on registry data, as well as the fact that cases had more comorbid conditions than controls (e.g. recent infection, chronic illnesses).
Bottom line: Recipients of glucocorticoids had an increased risk of VTE; the effect was strongest in new and recent users.
Citation: Johannesdottir SA, Horvath-Puho E, Dekkers OM, et al. Use of glucocorticoids and risk of venous thromboembolism. JAMA Intern Med. 2013;173(9):743-752.
Visit our website for more physician reviews of recent HM-relevant literature.
Clinical question: Is exogenous glucocorticoid administration associated with an increased risk of VTE?
Background: Endogenous hypercortisolism is linked to increased VTE rates, and pathophysiologic data exist to suggest glucocorticoids increase clotting, but few studies have measured the clinical link between glucocorticoid administration and VTE events.
Study design: Case-control study.
Setting: Denmark.
Synopsis: The authors analyzed Danish national registries, which include information on diagnoses and prescriptions. The study selection period was Jan. 1, 2005, to Dec. 31, 2011. During this period, 38,675 cases of VTE (both DVT and pulmonary embolism) were identified in the population of Denmark. These cases were matched with 387,650 controls. Three routes of glucocorticoid use were studied: systemic (oral and intravenous), inhaled, and intestinal-acting. Cases were classified as present (within 90 days of VTE event), recent (within 91 to 365 days), or former (more than 365 days prior) users of glucocorticoids. Categories were also created for new versus continuous users.
Glucocorticoid use was associated with a significant increase in VTE occurrence. The strongest link was in new and recent users, and the effect diminished over time. Key limitations of the study included its reliance on registry data, as well as the fact that cases had more comorbid conditions than controls (e.g. recent infection, chronic illnesses).
Bottom line: Recipients of glucocorticoids had an increased risk of VTE; the effect was strongest in new and recent users.
Citation: Johannesdottir SA, Horvath-Puho E, Dekkers OM, et al. Use of glucocorticoids and risk of venous thromboembolism. JAMA Intern Med. 2013;173(9):743-752.
Visit our website for more physician reviews of recent HM-relevant literature.
When is an answer not an answer?
When your beloved authors were studying research and statistics, around the time that Methuselah was celebrating his first birthday, we thought we knew the difference between hypothesis testing and hypothesis generating. With the former, you begin with a question, design a study to answer it, carry it out, and then do some statistical mumbo-jumbo on the data to determine if you have reasonable evidence to answer the question. With the latter, usually done after you’ve answered the main questions, you don’t have any preconceived idea of what’s going on, so you analyze anything that moves. We know that’s not really kosher, because the probability of finding something just by chance (a Type I error) increases astronomically as you do more tests.1 So, in the hypothesis generating phase, you don’t come to any conclusions; you just say, “That’s an interesting finding. Now we’ll have to do a real study to see if our observation holds up.”
Click on the PDF icon at the top of this introduction to read the full article.
When your beloved authors were studying research and statistics, around the time that Methuselah was celebrating his first birthday, we thought we knew the difference between hypothesis testing and hypothesis generating. With the former, you begin with a question, design a study to answer it, carry it out, and then do some statistical mumbo-jumbo on the data to determine if you have reasonable evidence to answer the question. With the latter, usually done after you’ve answered the main questions, you don’t have any preconceived idea of what’s going on, so you analyze anything that moves. We know that’s not really kosher, because the probability of finding something just by chance (a Type I error) increases astronomically as you do more tests.1 So, in the hypothesis generating phase, you don’t come to any conclusions; you just say, “That’s an interesting finding. Now we’ll have to do a real study to see if our observation holds up.”
Click on the PDF icon at the top of this introduction to read the full article.
When your beloved authors were studying research and statistics, around the time that Methuselah was celebrating his first birthday, we thought we knew the difference between hypothesis testing and hypothesis generating. With the former, you begin with a question, design a study to answer it, carry it out, and then do some statistical mumbo-jumbo on the data to determine if you have reasonable evidence to answer the question. With the latter, usually done after you’ve answered the main questions, you don’t have any preconceived idea of what’s going on, so you analyze anything that moves. We know that’s not really kosher, because the probability of finding something just by chance (a Type I error) increases astronomically as you do more tests.1 So, in the hypothesis generating phase, you don’t come to any conclusions; you just say, “That’s an interesting finding. Now we’ll have to do a real study to see if our observation holds up.”
Click on the PDF icon at the top of this introduction to read the full article.
Adaptability and Resiliency of Military Families During Reunification: Results of a Longitudinal Study
Medicare Beneficiaries Likely Readmitted
For at least 25 years, approximately 20% of Medicare fee‐for‐service discharges have been followed by a hospital readmission within 30 days.[1, 2] Section 3025 of the Patient Protection and Affordable Care Act (ACA)[3] created escalating penalties for hospitals with higher than expected 30‐day readmission rates, and the Congressional Budget Office estimated this will reduce Medicare spending by over $7 billion between 2010 and 2019.[4]
Hospitals and physicians have begun developing strategies to identify which Medicare beneficiaries are most likely to be readmitted and use this information to design programs to reduce their readmission rate. Initially, penalties will be based on readmission rates after an index discharge with heart failure, myocardial infarction, and pneumonia.[5] Recently, the Centers for Medicare and Medicaid Services (CMS) released the Inpatient Prospective Payment System FY2014 proposed rule, which proposes to add 2 new readmission penalties beginning in FY2015: readmissions for hip/knee arthroplasty and chronic obstructive pulmonary disease.[6] Other countries are already penalizing hospitals with high readmission rates; for example, Germany is penalizing all readmissions that occur within a 30‐day period following admission.[7] In this brief report, we examine the characteristics of Medicare beneficiaries most likely to be readmitted within 30 days. We focus on readmission rates for all discharge conditions and all patient readmission rates, because we believe the language in the ACA ultimately points to an all‐inclusive approach.
METHODS
We used a nationally random 5% sample of all Medicare beneficiaries for the period between January 1, 2008 and September 30, 2008. To be included, beneficiaries must have both Part A and B coverage and live within the United States. Medicare Advantage patients were excluded because Medicare Advantage plans do not report the data in the same way as fee for service. We calculated the readmission rate as the number of admissions that were preceded by an at‐risk discharge within 30 days divided by the total number of at‐risk discharges. This definition included admissions to and discharges from sole community providers, Medicare‐dependent small rural hospitals, and critical access hospitals. We counted as at risk all live discharges from short‐term acute care hospitals that were not discharged against medical advice, discharged to a rehabilitation unit within an acute care hospital, or readmitted on day 0 (due to inconsistency with use of transfer coding). We only included discharges and readmissions to acute care hospitals and excluded hospitalizations in long‐term care facilities, rehabilitation facilities, skilled nursing homes, and other non‐acute care hospital facilities from being an index hospitalization. However, if the beneficiary was discharged to 1 of these facilities and then readmitted to an acute care hospital, the readmission was counted.
Each discharge was recorded as an independent event and we reset the readmission clock for a fresh 30‐day count each time the beneficiary was discharged. We examined the admission and readmission rate to determine if the rates varied by age, gender, reason for entitlement, racial characteristics, region of the country, number of chronic conditions, and whether the beneficiary is also enrolled in Medicaid (dual eligibles). We calculated the mean readmission rate for each diagnosis‐related group (DRG) and then used the probability of having a readmission for each DRG to calculate a case mix adjustment for each hospital. To calculate the chronic illness burden, we used a previously developed methodology for counting the number of chronic disease categories reported for the patient in the preceding year (2007).[8, 9] The classification system is maintained by the Agency for Health Care Research and Quality. We then used logistic regression to calculate the odds ratio of a discharge being readmitted based on these factors. We preformed statistical analysis using SAS version 9.1.3 (SAS Institute Inc., Cary, NC).
RESULTS
There were 434,999 hospital discharges that occurred in the first 9 months of 2008 in the 5% sample. There were 20.6% of Medicare beneficiaries hospitalized, and the overall readmission rate was 19.5%. Table 1 shows the odds ratios and 95% confidence intervals for the probability that a Medicare beneficiary will be readmitted within 30 days for variables including: age, sex, race, dual‐eligibility status, number of comorbid conditions, geographic region, and reason for entitlement. Of note, beneficiaries with 10 or more chronic conditions were more than 6 times more likely, and beneficiaries with 5 to 9 chronic conditions were more than 2.5 times more likely, to be readmitted than beneficiaries with 1 to 4 chronic conditions.
Variable | Estimate | 95% Confidence Limits |
---|---|---|
| ||
Age 144 years | 1.634 | 1.5071.771 |
Age 4564 years | 1.231 | 1.1421.327 |
Age 7584 years | 1.048 | 1.0271.069 |
Age 85+ years | 1.141 | 1.1151.168 |
Age 6574 years | REF | |
Male | 1.201 | 1.1831.220 |
Black | 1.250 | 1.2211.280 |
Other race | 1.071 | 1.0331.111 |
White | REF | |
Dual eligibles | 1.173 | 1.1511.195 |
Northeast region | 1.146 | 1.1151.178 |
Midwest region | 1.092 | 1.0631.122 |
South region | 1.037 | 1.0111.063 |
West region | REF | |
0 comorbidities | 0.255 | 0.1480.441 |
59 comorbidities | 2.533 | 2.4492.621 |
10+ comorbidities | 6.119 | 5.9136.332 |
14 comorbidities | REF | |
Disabled | 0.817 | 0.7570.880 |
ESRD | 1.327 | 1.2231.440 |
Age >64 years | REF |
DISCUSSION
The most interesting finding is that beneficiaries with 10 or more chronic conditions were more than 6 times more likely to be readmitted than beneficiaries with 1 to 4 chronic conditions. Beneficiaries with 10 or more chronic conditions represent only 8.9% of all Medicare beneficiaries (31.0% of all hospitalizations), but they were responsible for 50.2% of all readmissions. The 31.8% of beneficiaries with 5 to 9 chronic conditions (55.5% of all hospitalizations) had the second highest odds ratio (2.5) and were responsible for 45% of all readmissions. The 59.3% of beneficiaries with <5 comorbidities (13.6% of all hospitalizations) were associated with only 4.7% of all readmissions. This strongly suggests that hospitals focus their attention on beneficiaries with 10 or more comorbidities. These results were despite correction for DRG diagnosis in the model.
We recognize that the number of chronic conditions is a crude measure of health status because it weighs hundreds of different clinical conditions equally; however, it seems a good proxy for 3 closely allied concepts: (1) the overall burden of chronic illness carried by the patient, (2) the patient's level of engagement with the healthcare system (including number of unique providers), and (3) the number of conditions being treated. By providing a 1‐year window of a patient's health status, it is a more complete picture than any single hospital claim submission or indices based solely on hospital discharge data.
The other variables are less predictive of 30‐day readmissions. Beneficiaries over 85 years old are only 14% more likely, whereas disabled Medicare beneficiaries <44 years old are 63% more likely to be readmitted than beneficiaries between 65 and 74 years old. Men are 20% more likely to be readmitted than women. Black race and dual‐eligibility slightly increase rates of readmission. Beneficiaries located in the West have the lowest readmission rates. In comparison to those who are aged, those with end‐stage renal disease (ESRD) have a higher rate of readmission, and those with a disability have a lower rate of readmission. In considering the age and reason for entitlement findings, one would assume that ESRD was the driver of higher readmission rates in the younger Medicare population.
CMS will need to analyze which hospitals have higher than expected readmission rates, and this will require risk adjustment at each hospital. In addition to the number of chronic conditions and other variables shown in Table 1, other factors CMS might want to include when it starts doing readmissions for all discharges is the discharge diagnosis (because our results suggest there are significant differences in the probability of a readmission across DRGs). In addition, CMS will need to consider how to capture additional data not currently in the claims data, such as social factors like homelessness.
We recognize significant limitations to these findings. First, this analysis uses only information that is available from Medicare claims and administrative data. Claims give almost no information on how well the hospital planned the discharge, instructed the patient and family, or engaged follow‐up providers. Also, claims data tell us virtually nothing about a patient's health literacy or social situation. Second, the analysis relies on claims data, but this has little clinical detail. Third, these data are limited to persons enrolled in fee‐for‐service Medicare. Fourth, we included all readmissions, including some readmissions (such as chemotherapy and staged percutaneous coronary interventions) that were part of a planned treatment protocol.[10] Fifth, we were unable to distinguish same‐day readmissions versus transfers, and therefore excluded all same‐day readmissions from measurement.
As hospitals and physicians begin to plan for the regulations that will penalize hospitals with high readmission rates, they will need to strongly consider targeting beneficiaries with more than 10 chronic conditions.
Acknowledgments
The Commonwealth Fund provided a grant to Dr. Anderson to help support this work. The authors report no conflicts of interest.
- Hospital readmissions in the Medicare population. N Engl J Med. 1984;311:1349–1353. , .
- Rehospitalizations among patients in the Medicare fee‐for‐service program. N Engl J Med. 2009;360:1418–1428. , , .
- Patient Protection and Affordable Care Act. Section 3025. Available at: http://www.gpo.gov/fdsys/pkg/PLAW‐111publ148/pdf/PLAW‐111publ148.pdf. Accessed April 8, 2013.
- Congressional Budget Office.Patient Protection and Affordable Care Act. Available at: http://www.cbo.gov/doc.cfm?index=10868. Accessed April 8, 2013.
- 2012 measures maintenance technical report: acute myocardial infarction, heart failure, and pneumonia 30‐day risk‐standardized readmission measures. Available at: http://www.qualitynet.org/dcs/ContentServer?c=Page78:27597–27599. , , , et al.
- Hospital payment based on diagnosis‐related groups differs in Europe and holds lessons for the United States. Health Aff (Millwood). 2013;32:713–723. , , , , .
- Out‐of‐pocket medical spending for care of chronic conditions. Health Aff (Millwood). 2001;20:267–278. , , , .
- MEPS data documentation HC‐006: 1996 medical conditions. Pub. no. 99‐DP06. Rockville, MD: AHRQ; 1999.
- Planned readmissions: a potential solution. Arch Intern Med. 2012;172:269–270. , .
For at least 25 years, approximately 20% of Medicare fee‐for‐service discharges have been followed by a hospital readmission within 30 days.[1, 2] Section 3025 of the Patient Protection and Affordable Care Act (ACA)[3] created escalating penalties for hospitals with higher than expected 30‐day readmission rates, and the Congressional Budget Office estimated this will reduce Medicare spending by over $7 billion between 2010 and 2019.[4]
Hospitals and physicians have begun developing strategies to identify which Medicare beneficiaries are most likely to be readmitted and use this information to design programs to reduce their readmission rate. Initially, penalties will be based on readmission rates after an index discharge with heart failure, myocardial infarction, and pneumonia.[5] Recently, the Centers for Medicare and Medicaid Services (CMS) released the Inpatient Prospective Payment System FY2014 proposed rule, which proposes to add 2 new readmission penalties beginning in FY2015: readmissions for hip/knee arthroplasty and chronic obstructive pulmonary disease.[6] Other countries are already penalizing hospitals with high readmission rates; for example, Germany is penalizing all readmissions that occur within a 30‐day period following admission.[7] In this brief report, we examine the characteristics of Medicare beneficiaries most likely to be readmitted within 30 days. We focus on readmission rates for all discharge conditions and all patient readmission rates, because we believe the language in the ACA ultimately points to an all‐inclusive approach.
METHODS
We used a nationally random 5% sample of all Medicare beneficiaries for the period between January 1, 2008 and September 30, 2008. To be included, beneficiaries must have both Part A and B coverage and live within the United States. Medicare Advantage patients were excluded because Medicare Advantage plans do not report the data in the same way as fee for service. We calculated the readmission rate as the number of admissions that were preceded by an at‐risk discharge within 30 days divided by the total number of at‐risk discharges. This definition included admissions to and discharges from sole community providers, Medicare‐dependent small rural hospitals, and critical access hospitals. We counted as at risk all live discharges from short‐term acute care hospitals that were not discharged against medical advice, discharged to a rehabilitation unit within an acute care hospital, or readmitted on day 0 (due to inconsistency with use of transfer coding). We only included discharges and readmissions to acute care hospitals and excluded hospitalizations in long‐term care facilities, rehabilitation facilities, skilled nursing homes, and other non‐acute care hospital facilities from being an index hospitalization. However, if the beneficiary was discharged to 1 of these facilities and then readmitted to an acute care hospital, the readmission was counted.
Each discharge was recorded as an independent event and we reset the readmission clock for a fresh 30‐day count each time the beneficiary was discharged. We examined the admission and readmission rate to determine if the rates varied by age, gender, reason for entitlement, racial characteristics, region of the country, number of chronic conditions, and whether the beneficiary is also enrolled in Medicaid (dual eligibles). We calculated the mean readmission rate for each diagnosis‐related group (DRG) and then used the probability of having a readmission for each DRG to calculate a case mix adjustment for each hospital. To calculate the chronic illness burden, we used a previously developed methodology for counting the number of chronic disease categories reported for the patient in the preceding year (2007).[8, 9] The classification system is maintained by the Agency for Health Care Research and Quality. We then used logistic regression to calculate the odds ratio of a discharge being readmitted based on these factors. We preformed statistical analysis using SAS version 9.1.3 (SAS Institute Inc., Cary, NC).
RESULTS
There were 434,999 hospital discharges that occurred in the first 9 months of 2008 in the 5% sample. There were 20.6% of Medicare beneficiaries hospitalized, and the overall readmission rate was 19.5%. Table 1 shows the odds ratios and 95% confidence intervals for the probability that a Medicare beneficiary will be readmitted within 30 days for variables including: age, sex, race, dual‐eligibility status, number of comorbid conditions, geographic region, and reason for entitlement. Of note, beneficiaries with 10 or more chronic conditions were more than 6 times more likely, and beneficiaries with 5 to 9 chronic conditions were more than 2.5 times more likely, to be readmitted than beneficiaries with 1 to 4 chronic conditions.
Variable | Estimate | 95% Confidence Limits |
---|---|---|
| ||
Age 144 years | 1.634 | 1.5071.771 |
Age 4564 years | 1.231 | 1.1421.327 |
Age 7584 years | 1.048 | 1.0271.069 |
Age 85+ years | 1.141 | 1.1151.168 |
Age 6574 years | REF | |
Male | 1.201 | 1.1831.220 |
Black | 1.250 | 1.2211.280 |
Other race | 1.071 | 1.0331.111 |
White | REF | |
Dual eligibles | 1.173 | 1.1511.195 |
Northeast region | 1.146 | 1.1151.178 |
Midwest region | 1.092 | 1.0631.122 |
South region | 1.037 | 1.0111.063 |
West region | REF | |
0 comorbidities | 0.255 | 0.1480.441 |
59 comorbidities | 2.533 | 2.4492.621 |
10+ comorbidities | 6.119 | 5.9136.332 |
14 comorbidities | REF | |
Disabled | 0.817 | 0.7570.880 |
ESRD | 1.327 | 1.2231.440 |
Age >64 years | REF |
DISCUSSION
The most interesting finding is that beneficiaries with 10 or more chronic conditions were more than 6 times more likely to be readmitted than beneficiaries with 1 to 4 chronic conditions. Beneficiaries with 10 or more chronic conditions represent only 8.9% of all Medicare beneficiaries (31.0% of all hospitalizations), but they were responsible for 50.2% of all readmissions. The 31.8% of beneficiaries with 5 to 9 chronic conditions (55.5% of all hospitalizations) had the second highest odds ratio (2.5) and were responsible for 45% of all readmissions. The 59.3% of beneficiaries with <5 comorbidities (13.6% of all hospitalizations) were associated with only 4.7% of all readmissions. This strongly suggests that hospitals focus their attention on beneficiaries with 10 or more comorbidities. These results were despite correction for DRG diagnosis in the model.
We recognize that the number of chronic conditions is a crude measure of health status because it weighs hundreds of different clinical conditions equally; however, it seems a good proxy for 3 closely allied concepts: (1) the overall burden of chronic illness carried by the patient, (2) the patient's level of engagement with the healthcare system (including number of unique providers), and (3) the number of conditions being treated. By providing a 1‐year window of a patient's health status, it is a more complete picture than any single hospital claim submission or indices based solely on hospital discharge data.
The other variables are less predictive of 30‐day readmissions. Beneficiaries over 85 years old are only 14% more likely, whereas disabled Medicare beneficiaries <44 years old are 63% more likely to be readmitted than beneficiaries between 65 and 74 years old. Men are 20% more likely to be readmitted than women. Black race and dual‐eligibility slightly increase rates of readmission. Beneficiaries located in the West have the lowest readmission rates. In comparison to those who are aged, those with end‐stage renal disease (ESRD) have a higher rate of readmission, and those with a disability have a lower rate of readmission. In considering the age and reason for entitlement findings, one would assume that ESRD was the driver of higher readmission rates in the younger Medicare population.
CMS will need to analyze which hospitals have higher than expected readmission rates, and this will require risk adjustment at each hospital. In addition to the number of chronic conditions and other variables shown in Table 1, other factors CMS might want to include when it starts doing readmissions for all discharges is the discharge diagnosis (because our results suggest there are significant differences in the probability of a readmission across DRGs). In addition, CMS will need to consider how to capture additional data not currently in the claims data, such as social factors like homelessness.
We recognize significant limitations to these findings. First, this analysis uses only information that is available from Medicare claims and administrative data. Claims give almost no information on how well the hospital planned the discharge, instructed the patient and family, or engaged follow‐up providers. Also, claims data tell us virtually nothing about a patient's health literacy or social situation. Second, the analysis relies on claims data, but this has little clinical detail. Third, these data are limited to persons enrolled in fee‐for‐service Medicare. Fourth, we included all readmissions, including some readmissions (such as chemotherapy and staged percutaneous coronary interventions) that were part of a planned treatment protocol.[10] Fifth, we were unable to distinguish same‐day readmissions versus transfers, and therefore excluded all same‐day readmissions from measurement.
As hospitals and physicians begin to plan for the regulations that will penalize hospitals with high readmission rates, they will need to strongly consider targeting beneficiaries with more than 10 chronic conditions.
Acknowledgments
The Commonwealth Fund provided a grant to Dr. Anderson to help support this work. The authors report no conflicts of interest.
For at least 25 years, approximately 20% of Medicare fee‐for‐service discharges have been followed by a hospital readmission within 30 days.[1, 2] Section 3025 of the Patient Protection and Affordable Care Act (ACA)[3] created escalating penalties for hospitals with higher than expected 30‐day readmission rates, and the Congressional Budget Office estimated this will reduce Medicare spending by over $7 billion between 2010 and 2019.[4]
Hospitals and physicians have begun developing strategies to identify which Medicare beneficiaries are most likely to be readmitted and use this information to design programs to reduce their readmission rate. Initially, penalties will be based on readmission rates after an index discharge with heart failure, myocardial infarction, and pneumonia.[5] Recently, the Centers for Medicare and Medicaid Services (CMS) released the Inpatient Prospective Payment System FY2014 proposed rule, which proposes to add 2 new readmission penalties beginning in FY2015: readmissions for hip/knee arthroplasty and chronic obstructive pulmonary disease.[6] Other countries are already penalizing hospitals with high readmission rates; for example, Germany is penalizing all readmissions that occur within a 30‐day period following admission.[7] In this brief report, we examine the characteristics of Medicare beneficiaries most likely to be readmitted within 30 days. We focus on readmission rates for all discharge conditions and all patient readmission rates, because we believe the language in the ACA ultimately points to an all‐inclusive approach.
METHODS
We used a nationally random 5% sample of all Medicare beneficiaries for the period between January 1, 2008 and September 30, 2008. To be included, beneficiaries must have both Part A and B coverage and live within the United States. Medicare Advantage patients were excluded because Medicare Advantage plans do not report the data in the same way as fee for service. We calculated the readmission rate as the number of admissions that were preceded by an at‐risk discharge within 30 days divided by the total number of at‐risk discharges. This definition included admissions to and discharges from sole community providers, Medicare‐dependent small rural hospitals, and critical access hospitals. We counted as at risk all live discharges from short‐term acute care hospitals that were not discharged against medical advice, discharged to a rehabilitation unit within an acute care hospital, or readmitted on day 0 (due to inconsistency with use of transfer coding). We only included discharges and readmissions to acute care hospitals and excluded hospitalizations in long‐term care facilities, rehabilitation facilities, skilled nursing homes, and other non‐acute care hospital facilities from being an index hospitalization. However, if the beneficiary was discharged to 1 of these facilities and then readmitted to an acute care hospital, the readmission was counted.
Each discharge was recorded as an independent event and we reset the readmission clock for a fresh 30‐day count each time the beneficiary was discharged. We examined the admission and readmission rate to determine if the rates varied by age, gender, reason for entitlement, racial characteristics, region of the country, number of chronic conditions, and whether the beneficiary is also enrolled in Medicaid (dual eligibles). We calculated the mean readmission rate for each diagnosis‐related group (DRG) and then used the probability of having a readmission for each DRG to calculate a case mix adjustment for each hospital. To calculate the chronic illness burden, we used a previously developed methodology for counting the number of chronic disease categories reported for the patient in the preceding year (2007).[8, 9] The classification system is maintained by the Agency for Health Care Research and Quality. We then used logistic regression to calculate the odds ratio of a discharge being readmitted based on these factors. We preformed statistical analysis using SAS version 9.1.3 (SAS Institute Inc., Cary, NC).
RESULTS
There were 434,999 hospital discharges that occurred in the first 9 months of 2008 in the 5% sample. There were 20.6% of Medicare beneficiaries hospitalized, and the overall readmission rate was 19.5%. Table 1 shows the odds ratios and 95% confidence intervals for the probability that a Medicare beneficiary will be readmitted within 30 days for variables including: age, sex, race, dual‐eligibility status, number of comorbid conditions, geographic region, and reason for entitlement. Of note, beneficiaries with 10 or more chronic conditions were more than 6 times more likely, and beneficiaries with 5 to 9 chronic conditions were more than 2.5 times more likely, to be readmitted than beneficiaries with 1 to 4 chronic conditions.
Variable | Estimate | 95% Confidence Limits |
---|---|---|
| ||
Age 144 years | 1.634 | 1.5071.771 |
Age 4564 years | 1.231 | 1.1421.327 |
Age 7584 years | 1.048 | 1.0271.069 |
Age 85+ years | 1.141 | 1.1151.168 |
Age 6574 years | REF | |
Male | 1.201 | 1.1831.220 |
Black | 1.250 | 1.2211.280 |
Other race | 1.071 | 1.0331.111 |
White | REF | |
Dual eligibles | 1.173 | 1.1511.195 |
Northeast region | 1.146 | 1.1151.178 |
Midwest region | 1.092 | 1.0631.122 |
South region | 1.037 | 1.0111.063 |
West region | REF | |
0 comorbidities | 0.255 | 0.1480.441 |
59 comorbidities | 2.533 | 2.4492.621 |
10+ comorbidities | 6.119 | 5.9136.332 |
14 comorbidities | REF | |
Disabled | 0.817 | 0.7570.880 |
ESRD | 1.327 | 1.2231.440 |
Age >64 years | REF |
DISCUSSION
The most interesting finding is that beneficiaries with 10 or more chronic conditions were more than 6 times more likely to be readmitted than beneficiaries with 1 to 4 chronic conditions. Beneficiaries with 10 or more chronic conditions represent only 8.9% of all Medicare beneficiaries (31.0% of all hospitalizations), but they were responsible for 50.2% of all readmissions. The 31.8% of beneficiaries with 5 to 9 chronic conditions (55.5% of all hospitalizations) had the second highest odds ratio (2.5) and were responsible for 45% of all readmissions. The 59.3% of beneficiaries with <5 comorbidities (13.6% of all hospitalizations) were associated with only 4.7% of all readmissions. This strongly suggests that hospitals focus their attention on beneficiaries with 10 or more comorbidities. These results were despite correction for DRG diagnosis in the model.
We recognize that the number of chronic conditions is a crude measure of health status because it weighs hundreds of different clinical conditions equally; however, it seems a good proxy for 3 closely allied concepts: (1) the overall burden of chronic illness carried by the patient, (2) the patient's level of engagement with the healthcare system (including number of unique providers), and (3) the number of conditions being treated. By providing a 1‐year window of a patient's health status, it is a more complete picture than any single hospital claim submission or indices based solely on hospital discharge data.
The other variables are less predictive of 30‐day readmissions. Beneficiaries over 85 years old are only 14% more likely, whereas disabled Medicare beneficiaries <44 years old are 63% more likely to be readmitted than beneficiaries between 65 and 74 years old. Men are 20% more likely to be readmitted than women. Black race and dual‐eligibility slightly increase rates of readmission. Beneficiaries located in the West have the lowest readmission rates. In comparison to those who are aged, those with end‐stage renal disease (ESRD) have a higher rate of readmission, and those with a disability have a lower rate of readmission. In considering the age and reason for entitlement findings, one would assume that ESRD was the driver of higher readmission rates in the younger Medicare population.
CMS will need to analyze which hospitals have higher than expected readmission rates, and this will require risk adjustment at each hospital. In addition to the number of chronic conditions and other variables shown in Table 1, other factors CMS might want to include when it starts doing readmissions for all discharges is the discharge diagnosis (because our results suggest there are significant differences in the probability of a readmission across DRGs). In addition, CMS will need to consider how to capture additional data not currently in the claims data, such as social factors like homelessness.
We recognize significant limitations to these findings. First, this analysis uses only information that is available from Medicare claims and administrative data. Claims give almost no information on how well the hospital planned the discharge, instructed the patient and family, or engaged follow‐up providers. Also, claims data tell us virtually nothing about a patient's health literacy or social situation. Second, the analysis relies on claims data, but this has little clinical detail. Third, these data are limited to persons enrolled in fee‐for‐service Medicare. Fourth, we included all readmissions, including some readmissions (such as chemotherapy and staged percutaneous coronary interventions) that were part of a planned treatment protocol.[10] Fifth, we were unable to distinguish same‐day readmissions versus transfers, and therefore excluded all same‐day readmissions from measurement.
As hospitals and physicians begin to plan for the regulations that will penalize hospitals with high readmission rates, they will need to strongly consider targeting beneficiaries with more than 10 chronic conditions.
Acknowledgments
The Commonwealth Fund provided a grant to Dr. Anderson to help support this work. The authors report no conflicts of interest.
- Hospital readmissions in the Medicare population. N Engl J Med. 1984;311:1349–1353. , .
- Rehospitalizations among patients in the Medicare fee‐for‐service program. N Engl J Med. 2009;360:1418–1428. , , .
- Patient Protection and Affordable Care Act. Section 3025. Available at: http://www.gpo.gov/fdsys/pkg/PLAW‐111publ148/pdf/PLAW‐111publ148.pdf. Accessed April 8, 2013.
- Congressional Budget Office.Patient Protection and Affordable Care Act. Available at: http://www.cbo.gov/doc.cfm?index=10868. Accessed April 8, 2013.
- 2012 measures maintenance technical report: acute myocardial infarction, heart failure, and pneumonia 30‐day risk‐standardized readmission measures. Available at: http://www.qualitynet.org/dcs/ContentServer?c=Page78:27597–27599. , , , et al.
- Hospital payment based on diagnosis‐related groups differs in Europe and holds lessons for the United States. Health Aff (Millwood). 2013;32:713–723. , , , , .
- Out‐of‐pocket medical spending for care of chronic conditions. Health Aff (Millwood). 2001;20:267–278. , , , .
- MEPS data documentation HC‐006: 1996 medical conditions. Pub. no. 99‐DP06. Rockville, MD: AHRQ; 1999.
- Planned readmissions: a potential solution. Arch Intern Med. 2012;172:269–270. , .
- Hospital readmissions in the Medicare population. N Engl J Med. 1984;311:1349–1353. , .
- Rehospitalizations among patients in the Medicare fee‐for‐service program. N Engl J Med. 2009;360:1418–1428. , , .
- Patient Protection and Affordable Care Act. Section 3025. Available at: http://www.gpo.gov/fdsys/pkg/PLAW‐111publ148/pdf/PLAW‐111publ148.pdf. Accessed April 8, 2013.
- Congressional Budget Office.Patient Protection and Affordable Care Act. Available at: http://www.cbo.gov/doc.cfm?index=10868. Accessed April 8, 2013.
- 2012 measures maintenance technical report: acute myocardial infarction, heart failure, and pneumonia 30‐day risk‐standardized readmission measures. Available at: http://www.qualitynet.org/dcs/ContentServer?c=Page78:27597–27599. , , , et al.
- Hospital payment based on diagnosis‐related groups differs in Europe and holds lessons for the United States. Health Aff (Millwood). 2013;32:713–723. , , , , .
- Out‐of‐pocket medical spending for care of chronic conditions. Health Aff (Millwood). 2001;20:267–278. , , , .
- MEPS data documentation HC‐006: 1996 medical conditions. Pub. no. 99‐DP06. Rockville, MD: AHRQ; 1999.
- Planned readmissions: a potential solution. Arch Intern Med. 2012;172:269–270. , .
Dear Doctor: A Patient‐Centered Tool
In their seminal report Crossing the Quality Chasm, the Institute of Medicine outlined patient‐centered care as 1 of its 6 aims to improve the healthcare delivery system.[1] Patients who are more involved in their diagnosis and treatment plan are more likely to feel respected, be satisfied with their healthcare experience, and ultimately have better outcomes.[2, 3] In a study of hospitalized patients, only 42% were able to state their diagnosis at the time of discharge, suggesting that hospital providers could communicate better with patients about their hospital care.[4] Additionally, only 28% of hospitalized patients were able to list their medications, and only 37% were able to state the purpose of their medications. Although hospitals have taken great strides to improve the quality of patient care, publicly reported patient care surveys, such as the Hospital Consumer Assessment of Hospitals and Health Systems (HCAHPS), suggest that physician communication with patients could be further improved.[1, 5] Furthermore, a recent report by the Institute of Medicine stresses the need to get patients and families involved in their care.[6] Thus, hospital‐based providers should seek to enhance the quality of their communication with patients.
With greater emphasis placed on patient‐ and family‐centered care at many health systems, simple and easy‐to‐implement strategies to improve communication with patients need to be developed and tested.[7, 8] Patients who actively participate in their healthcare by asking questions of their doctor are able to control the focus of their interaction and adjust the amount of information provided.[9] Simply asking questions can have a critical impact, as 1 study found that the frequency with which patients asked questions was significantly related to the amount of information received about general and specific medical matters.[10] The notepad is a common tool for reminders and personal interactions that is used in everyday life, but has not been formalized in the hospital. We introduced Dear Doctor (DD) notes, a bedside notepad designed to prompt patient questions, with the goal of facilitating patient communication with their hospitalist physicians (Figure 1). As hospitalists provide direct and indirect care to a growing number of hospitalized patients, they are likely to be asked questions and opinions about the patients' diagnoses and plans. Furthermore, hospitalists are poised to lead institutional quality, safety, efficiency, and service improvement efforts in the inpatient setting. Becoming familiar with communication‐enhancing tools, such as the DD notes, may help hospitalists in their improvement team roles.

METHODS
Setting
We conducted a study between July 2009 and September 2009 on inpatient medical wards at a large academic medical center with 610 beds and over 44,000 annual discharges.[11] The internal medicine services served by attending physicians and residents comprise a large proportion of hospitalized patients, accounting for over 17,000 discharges per year. Each medical unit includes 32 beds.
Population
Patients over the age of 18 years admitted to a general medicine or cardiology unit and who were able to verbally communicate in English were eligible to be surveyed in the study. Patients with a length of stay <24 hours were excluded. A total of 664 patients were surveyed for inclusion in the study, 440 patients in the intervention group and 224 patients in the control group.
Intervention
The DD notepad included sample questions and informational prompts derived with input from a community focus group. The community focus group consisted of current and formerly hospitalized patients and family members who were asked by members of the study group what they thought would be important to include on a notepad provided to patients. From their answers the study team developed the DD notepad prototype. The DD notepad included 3 general categories of questions: (1) diagnosis and treatment, (2) tests and procedures, and (3) medications. To address other miscellaneous topics such as discharge and posthospital care needs, a section was designated for the patient to check off as I have a few more questions (Use the back of the sheet).
All patients admitted to the study units were intended to receive the DD notepad and pen, which were placed on the bedside table during the room change by our custodial staff. Patients who did not receive DD notepads in the intervention group during their first hospitalization day were provided with 1 by the clinical assistants working with the hospitalists. These patients did not initially receive the notepad due to logistical reasons from temporary rotating staff who were not instructed to provide the notepads. Patients were not formally prompted to use the notepad. Hospitalists, residents, and nurses on the study units were informed about the distribution of DD notes to patients on these units; however, they were not provided with any specific instructions on how they should incorporate the DD notes into their interactions with their patients. The use of the DD notepad was left to each healthcare professional's own discretion.
Members of the study team surveyed patients who had been in the hospital for a minimum of 24 hours in the intervention and control groups twice weekly. All responses were deidentified of any personal or health information. Patients were asked to rate on a scale from 1 to 5 their use of the DD notepads, their perceived value, the circumstances in which the notepads were used, and their level of satisfaction with how their physicians communicated and answered their questions (1 = no improvement, 5 = significant improvement). For control patients, questions pertaining to DD notepads were not applicable and were therefore excluded.
Statistical Analysis
The data were analyzed in an intention‐to‐treat analysis of all 440 patients in the intervention group. Intervention and control groups were compared using 2, rank sum, and Fisher exact statistical tests, with significance assigned as P < 0.05, using SPSS software version 17.0 (SPSS, Inc., Chicago, IL). Our project was approved by the University of Michigan's institutional review board.
RESULTS
Of the 440 patients surveyed in the intervention group (1 general medicine and 1 cardiology unit), 343 (78%) received the notepads in their rooms and 207 (47%) used them (Figure 2). Not every patient in the intervention group received DD notepads due to inconsistent placement of DD notepads upon every room turnover. Of the patients admitted to the control group (1 general medicine and 1 cardiology unit), 224 were surveyed. Fifty‐four percent of the 440 patients in the intervention group reported that they took notes related to their hospital care, compared to only 22% of the 224 patients in the control group (P < 0.001). Of the patients who took notes within the intervention group (n = 207), 91% of them utilized the DD notepads.

Patients in the intervention group who received and used the DD notes (n = 207) compared to patients in the control group (n = 224) were more likely to report that their questions were answered by their physicians (4.63 vs 4.45, P < 0.001). In an intention‐to‐treat analysis of all 440 patients in the intervention group, the overall satisfaction with physician communication was not significantly different between the intervention and control groups as measured on a 5‐point Likert scale (4.55 vs 4.55, P = 0.89). However, 89% of the patients in the intervention group who used the notepads felt that DD notepads either moderately or significantly improved their communication with their providers (Figure 3).

When the 207 patients who received DD notepads were asked how they used this tool, 99% of these patients used DD to write down questions, 82% to keep track of tests and procedures, and 54% indicated that their family and friends also used the notepads during the hospital stay (Table 1). Among these patients who utilized the DD notepads, 93% reported that they would use them again in the future.
Wrote Notes? (P < 0.001) (%) | Used DD? (%) | Use in Future? (%) | Frequency of Questions Answered (P < 0.001) | DD Improved Communication | Satisfied With Communication? (P = 0.89) | |
---|---|---|---|---|---|---|
| ||||||
Intervention (n = 440) | 54 | 91 | 93.2 | 4.63 | 3.76 | 4.55 |
Control (n = 224) | 22 | 4.45 | 4.55 |
Of the 97 patients in the intervention group who did not receive a DD notepad, we asked if they would use the DD notepad if they were made aware of such a tool. Of these patients, 77% agreed that they would use DD notes if they were made available in the future, 100% of them said that they would use DD to write down questions, 97% indicated that they would write notes about tests and procedures, and 88% of them believed that their families and friends would use DD notes.
DISCUSSION
As hospitals place greater emphasis and value on patient‐centered care as part of their clinical mission, it is important to develop tools to help facilitate the doctor‐patient relationship. We found that patients who were provided the Dear Doctor notepad were more satisfied that their doctors answered their questions and felt this tool enhanced their ability to communicate with their physicians. Employing the use of a familiar tool such as the notepad to remind patients about specific issues in their interactions with their providers can be a powerful intervention. Our study demonstrated that the DD notepad was widely accepted by patients, and that almost all of them would use this tool if it were made available to them in the future.
Other tools and methods to enhance the quality of communication between patients and their healthcare providers have included using whiteboards in the patients' rooms to relay the care plan to the patients, implementing bedside rounds by the healthcare team, and multidisciplinary huddling to coordinate information to the patient.[12, 13] Studies of these communication tools have shown potential to improve teamwork, interaction, and patient care. All of these have their own merit and value, and our DD notepad should be considered an adjunct to existing methods to enhance the patient care experience. A bedside tool that is familiar in form to most patients also needs to have the feature of easy access and use. Once this barrier has been removed for the patient and their family members, tools such as the DD notepad can impact the patient‐centeredness by fostering increased and better quality dialogue between the patients, their family members, and healthcare providers.
The DD notepad represents a means of communication that may have the potential to empower patients. It is possible that through question prompts, the DD notepad stimulates the patient to be an active partner with his or her healthcare team. This may enable patients to have some sense of control and accountability of their care in a setting where they would otherwise feel overwhelmed or powerless. The 3 general categories to help patients write down their questions included diagnosis, treatment plan, and medications. In the inpatient setting, where patient‐care activities can be fast paced, and patients are unable to recall some details when speaking to the healthcare team, these notes may remind the patient to write their thoughts down so that they may be remembered for a future time. In situations where patients may not know which questions to ask, the question prompts may be particularly helpful. We did not assess whether our particular question prompts were the key elements that resulted in their perceived value, or whether simply placing a blank notepad at the bedside would also have been successful. However, the specific questions were suggested by the focus groups. Enhanced communication, focusing on the patients' understanding of their condition, and the need to pursue certain diagnostic or therapeutic interventions, may help patients to be better prepared for the next course of plan. These topics of reasons for hospitalization, treatment plan, and medication changes are also important for patients to be active participants in their care, in particular as they transition from 1 site of care to the next, and their healthcare will be delivered by different providers.
There are several limitations to our study. First, this intervention was performed at a single hospital site with only 2 clinical services (general medicine, cardiology) represented in the study groups. Although we do not have any causal reasons to believe this tool would be looked upon differently by patients on other clinical services, it is possible that patients on a different clinical unit or service may view this tool as less or more useful. Second, as the patients were not randomized to intervention, but rather based on the units to which they were admitted, it is possible that other variables, such as the experience of the unit staff, the patient's condition, and housestaff‐based service versus hospitalist‐based service may have played a role in how the patients perceived the use of DD notes. Third, patients were only surveyed if they were able to verbally communicate in English. These notes may not be as useful in hospital settings to populations with language or literacy barriers. Fourth, the logistical implementation of DD notes limited our ability to deliver the DD notepads in every patient's rooms, where only 78% of the intervention group received the DD notepads. This may be the reason that we did not find that overall satisfaction with physician communication differed between intervention and control groups. Nonetheless, we performed an intention‐to‐treat analysis to minimize any biases in our analysis. Last, although our survey of patients asked about their satisfaction in using the DD note pads, we did not compare these results with those of Press‐Ganey or HCAHPS scores of patients on the intervention group versus the control group. Additionally, lack of data about type, quality, and quantity of questions asked by a control group to see if the notepads actually improved quality of questions asked is a limitation; however, we believe our outcomes of interest were most specifically evaluated through our survey questions.
DD notes show that the majority of patients who use this tool feel a modest to significant improvement in communication with their providers. Although the quality of medical care is undoubtedly the first priority, the patients' view of their care, which includes communication, is arguably just as important. An often‐forgotten goal of hospitals and clinics is to provide service excellence along with high‐quality care. Thus, it is imperative for hospitals and their care providers to not only focus on the quality and safety of the clinical care, but also be mindful of the patient's entire experience throughout their hospital stay. Many of the categories of questions asked in the HCAHPS address the patient's experience and perspectives of hospital care. Furthermore, the role of the HCAHPS survey in the Value‐Based Purchasing rules may enhance the importance of these notepads. As the results of HCAHPS are becoming more transparent and available to the public, the impact of such results will have a greater significance to the future of the hospital's clinical mission.
CONCLUSION
DD notepads are a simple, low‐cost, patient‐centered tool that can be an effective reminder for patients to ask their healthcare providers questions related to their hospital care. Utilizing a common tool such as the notepad, redesigned for the healthcare setting, can serve to help healthcare providers interact with their patients. Patient satisfaction may be higher in patients who use the DD notepad.
Disclosures: Aaron S. Farberg, MD, and Andrew M. Lin, MD, contributed equally in every way and should be considered co‐first authors. This work was supported by a University of Michigan Fostering Innovations Grant. The authors have no conflicting financial interests.
- Committee on Quality of Health Care in America, Institute of Medicine. Crossing the Quality Chasm: A New Health System for the 21st Century. Washington, DC: National Academy Press; 2001.
- An evidence base for patient‐centered cancer care: a meta‐analysis of studies of observed communication between cancer specialists and their patients. Patient Educ Couns. 2009;77(3):379–383. , , , .
- Effective physician‐patient communication and health outcomes: a review. Can Med Assoc J. 1995;152:1423–1433. .
- Patients' understanding of their treatment plans and diagnosis at discharge. Mayo Clin Proc. 2005;80(8):991–994. , .
- Patients' perception of hospital care in the United States. N Engl J Med. 2008;359:1921–1931. , , , .
- Institute of Medicine of the National Academies.Best care at lower cost: the path to continuously learning health care in America. Available at: http://www.iom.edu/Reports/2012/Best‐Care‐at‐Lower‐Cost‐The‐Path‐to‐Continuously‐Learning‐Health‐Care‐in‐America.aspx. Accessed October 5, 2012.
- An introduction to technology for patient‐centered collaborative care. J Ambul Care Manage. 2006;29:195–198. , .
- Effect on health‐related outcome of interventions to alter the interaction between patients and practitioners: a systematic review of trials. Ann Fam Med. 2004;2(6):595–608 , , , , , .
- Characteristics of physicians with participatory decision‐making styles. Ann Intern Med. 1996;124(5):497–504. , , , , .
- Information‐giving consultations: the influence of patients' communicative styles and personal characteristics. Soc Sci Med. 1991:32(5):541–548. .
- University of Michigan Health System.Patient care and University of Michigan Health System. Available at: http://www.uofmhealth.org/about%2Bumhs/about‐clinical‐care. Accessed August 31, 2012.
- It's the writing on the wall: whiteboards improve inpatient satisfaction with provider communication. Am J Med Qual. 2011;26(2):127–131 , , , et al.
- Patient whiteboards as a communication tool in the hospital setting: a survey of practices and recommendations. J Hosp Med. 2010;5(4):234–239. , , , , .
In their seminal report Crossing the Quality Chasm, the Institute of Medicine outlined patient‐centered care as 1 of its 6 aims to improve the healthcare delivery system.[1] Patients who are more involved in their diagnosis and treatment plan are more likely to feel respected, be satisfied with their healthcare experience, and ultimately have better outcomes.[2, 3] In a study of hospitalized patients, only 42% were able to state their diagnosis at the time of discharge, suggesting that hospital providers could communicate better with patients about their hospital care.[4] Additionally, only 28% of hospitalized patients were able to list their medications, and only 37% were able to state the purpose of their medications. Although hospitals have taken great strides to improve the quality of patient care, publicly reported patient care surveys, such as the Hospital Consumer Assessment of Hospitals and Health Systems (HCAHPS), suggest that physician communication with patients could be further improved.[1, 5] Furthermore, a recent report by the Institute of Medicine stresses the need to get patients and families involved in their care.[6] Thus, hospital‐based providers should seek to enhance the quality of their communication with patients.
With greater emphasis placed on patient‐ and family‐centered care at many health systems, simple and easy‐to‐implement strategies to improve communication with patients need to be developed and tested.[7, 8] Patients who actively participate in their healthcare by asking questions of their doctor are able to control the focus of their interaction and adjust the amount of information provided.[9] Simply asking questions can have a critical impact, as 1 study found that the frequency with which patients asked questions was significantly related to the amount of information received about general and specific medical matters.[10] The notepad is a common tool for reminders and personal interactions that is used in everyday life, but has not been formalized in the hospital. We introduced Dear Doctor (DD) notes, a bedside notepad designed to prompt patient questions, with the goal of facilitating patient communication with their hospitalist physicians (Figure 1). As hospitalists provide direct and indirect care to a growing number of hospitalized patients, they are likely to be asked questions and opinions about the patients' diagnoses and plans. Furthermore, hospitalists are poised to lead institutional quality, safety, efficiency, and service improvement efforts in the inpatient setting. Becoming familiar with communication‐enhancing tools, such as the DD notes, may help hospitalists in their improvement team roles.

METHODS
Setting
We conducted a study between July 2009 and September 2009 on inpatient medical wards at a large academic medical center with 610 beds and over 44,000 annual discharges.[11] The internal medicine services served by attending physicians and residents comprise a large proportion of hospitalized patients, accounting for over 17,000 discharges per year. Each medical unit includes 32 beds.
Population
Patients over the age of 18 years admitted to a general medicine or cardiology unit and who were able to verbally communicate in English were eligible to be surveyed in the study. Patients with a length of stay <24 hours were excluded. A total of 664 patients were surveyed for inclusion in the study, 440 patients in the intervention group and 224 patients in the control group.
Intervention
The DD notepad included sample questions and informational prompts derived with input from a community focus group. The community focus group consisted of current and formerly hospitalized patients and family members who were asked by members of the study group what they thought would be important to include on a notepad provided to patients. From their answers the study team developed the DD notepad prototype. The DD notepad included 3 general categories of questions: (1) diagnosis and treatment, (2) tests and procedures, and (3) medications. To address other miscellaneous topics such as discharge and posthospital care needs, a section was designated for the patient to check off as I have a few more questions (Use the back of the sheet).
All patients admitted to the study units were intended to receive the DD notepad and pen, which were placed on the bedside table during the room change by our custodial staff. Patients who did not receive DD notepads in the intervention group during their first hospitalization day were provided with 1 by the clinical assistants working with the hospitalists. These patients did not initially receive the notepad due to logistical reasons from temporary rotating staff who were not instructed to provide the notepads. Patients were not formally prompted to use the notepad. Hospitalists, residents, and nurses on the study units were informed about the distribution of DD notes to patients on these units; however, they were not provided with any specific instructions on how they should incorporate the DD notes into their interactions with their patients. The use of the DD notepad was left to each healthcare professional's own discretion.
Members of the study team surveyed patients who had been in the hospital for a minimum of 24 hours in the intervention and control groups twice weekly. All responses were deidentified of any personal or health information. Patients were asked to rate on a scale from 1 to 5 their use of the DD notepads, their perceived value, the circumstances in which the notepads were used, and their level of satisfaction with how their physicians communicated and answered their questions (1 = no improvement, 5 = significant improvement). For control patients, questions pertaining to DD notepads were not applicable and were therefore excluded.
Statistical Analysis
The data were analyzed in an intention‐to‐treat analysis of all 440 patients in the intervention group. Intervention and control groups were compared using 2, rank sum, and Fisher exact statistical tests, with significance assigned as P < 0.05, using SPSS software version 17.0 (SPSS, Inc., Chicago, IL). Our project was approved by the University of Michigan's institutional review board.
RESULTS
Of the 440 patients surveyed in the intervention group (1 general medicine and 1 cardiology unit), 343 (78%) received the notepads in their rooms and 207 (47%) used them (Figure 2). Not every patient in the intervention group received DD notepads due to inconsistent placement of DD notepads upon every room turnover. Of the patients admitted to the control group (1 general medicine and 1 cardiology unit), 224 were surveyed. Fifty‐four percent of the 440 patients in the intervention group reported that they took notes related to their hospital care, compared to only 22% of the 224 patients in the control group (P < 0.001). Of the patients who took notes within the intervention group (n = 207), 91% of them utilized the DD notepads.

Patients in the intervention group who received and used the DD notes (n = 207) compared to patients in the control group (n = 224) were more likely to report that their questions were answered by their physicians (4.63 vs 4.45, P < 0.001). In an intention‐to‐treat analysis of all 440 patients in the intervention group, the overall satisfaction with physician communication was not significantly different between the intervention and control groups as measured on a 5‐point Likert scale (4.55 vs 4.55, P = 0.89). However, 89% of the patients in the intervention group who used the notepads felt that DD notepads either moderately or significantly improved their communication with their providers (Figure 3).

When the 207 patients who received DD notepads were asked how they used this tool, 99% of these patients used DD to write down questions, 82% to keep track of tests and procedures, and 54% indicated that their family and friends also used the notepads during the hospital stay (Table 1). Among these patients who utilized the DD notepads, 93% reported that they would use them again in the future.
Wrote Notes? (P < 0.001) (%) | Used DD? (%) | Use in Future? (%) | Frequency of Questions Answered (P < 0.001) | DD Improved Communication | Satisfied With Communication? (P = 0.89) | |
---|---|---|---|---|---|---|
| ||||||
Intervention (n = 440) | 54 | 91 | 93.2 | 4.63 | 3.76 | 4.55 |
Control (n = 224) | 22 | 4.45 | 4.55 |
Of the 97 patients in the intervention group who did not receive a DD notepad, we asked if they would use the DD notepad if they were made aware of such a tool. Of these patients, 77% agreed that they would use DD notes if they were made available in the future, 100% of them said that they would use DD to write down questions, 97% indicated that they would write notes about tests and procedures, and 88% of them believed that their families and friends would use DD notes.
DISCUSSION
As hospitals place greater emphasis and value on patient‐centered care as part of their clinical mission, it is important to develop tools to help facilitate the doctor‐patient relationship. We found that patients who were provided the Dear Doctor notepad were more satisfied that their doctors answered their questions and felt this tool enhanced their ability to communicate with their physicians. Employing the use of a familiar tool such as the notepad to remind patients about specific issues in their interactions with their providers can be a powerful intervention. Our study demonstrated that the DD notepad was widely accepted by patients, and that almost all of them would use this tool if it were made available to them in the future.
Other tools and methods to enhance the quality of communication between patients and their healthcare providers have included using whiteboards in the patients' rooms to relay the care plan to the patients, implementing bedside rounds by the healthcare team, and multidisciplinary huddling to coordinate information to the patient.[12, 13] Studies of these communication tools have shown potential to improve teamwork, interaction, and patient care. All of these have their own merit and value, and our DD notepad should be considered an adjunct to existing methods to enhance the patient care experience. A bedside tool that is familiar in form to most patients also needs to have the feature of easy access and use. Once this barrier has been removed for the patient and their family members, tools such as the DD notepad can impact the patient‐centeredness by fostering increased and better quality dialogue between the patients, their family members, and healthcare providers.
The DD notepad represents a means of communication that may have the potential to empower patients. It is possible that through question prompts, the DD notepad stimulates the patient to be an active partner with his or her healthcare team. This may enable patients to have some sense of control and accountability of their care in a setting where they would otherwise feel overwhelmed or powerless. The 3 general categories to help patients write down their questions included diagnosis, treatment plan, and medications. In the inpatient setting, where patient‐care activities can be fast paced, and patients are unable to recall some details when speaking to the healthcare team, these notes may remind the patient to write their thoughts down so that they may be remembered for a future time. In situations where patients may not know which questions to ask, the question prompts may be particularly helpful. We did not assess whether our particular question prompts were the key elements that resulted in their perceived value, or whether simply placing a blank notepad at the bedside would also have been successful. However, the specific questions were suggested by the focus groups. Enhanced communication, focusing on the patients' understanding of their condition, and the need to pursue certain diagnostic or therapeutic interventions, may help patients to be better prepared for the next course of plan. These topics of reasons for hospitalization, treatment plan, and medication changes are also important for patients to be active participants in their care, in particular as they transition from 1 site of care to the next, and their healthcare will be delivered by different providers.
There are several limitations to our study. First, this intervention was performed at a single hospital site with only 2 clinical services (general medicine, cardiology) represented in the study groups. Although we do not have any causal reasons to believe this tool would be looked upon differently by patients on other clinical services, it is possible that patients on a different clinical unit or service may view this tool as less or more useful. Second, as the patients were not randomized to intervention, but rather based on the units to which they were admitted, it is possible that other variables, such as the experience of the unit staff, the patient's condition, and housestaff‐based service versus hospitalist‐based service may have played a role in how the patients perceived the use of DD notes. Third, patients were only surveyed if they were able to verbally communicate in English. These notes may not be as useful in hospital settings to populations with language or literacy barriers. Fourth, the logistical implementation of DD notes limited our ability to deliver the DD notepads in every patient's rooms, where only 78% of the intervention group received the DD notepads. This may be the reason that we did not find that overall satisfaction with physician communication differed between intervention and control groups. Nonetheless, we performed an intention‐to‐treat analysis to minimize any biases in our analysis. Last, although our survey of patients asked about their satisfaction in using the DD note pads, we did not compare these results with those of Press‐Ganey or HCAHPS scores of patients on the intervention group versus the control group. Additionally, lack of data about type, quality, and quantity of questions asked by a control group to see if the notepads actually improved quality of questions asked is a limitation; however, we believe our outcomes of interest were most specifically evaluated through our survey questions.
DD notes show that the majority of patients who use this tool feel a modest to significant improvement in communication with their providers. Although the quality of medical care is undoubtedly the first priority, the patients' view of their care, which includes communication, is arguably just as important. An often‐forgotten goal of hospitals and clinics is to provide service excellence along with high‐quality care. Thus, it is imperative for hospitals and their care providers to not only focus on the quality and safety of the clinical care, but also be mindful of the patient's entire experience throughout their hospital stay. Many of the categories of questions asked in the HCAHPS address the patient's experience and perspectives of hospital care. Furthermore, the role of the HCAHPS survey in the Value‐Based Purchasing rules may enhance the importance of these notepads. As the results of HCAHPS are becoming more transparent and available to the public, the impact of such results will have a greater significance to the future of the hospital's clinical mission.
CONCLUSION
DD notepads are a simple, low‐cost, patient‐centered tool that can be an effective reminder for patients to ask their healthcare providers questions related to their hospital care. Utilizing a common tool such as the notepad, redesigned for the healthcare setting, can serve to help healthcare providers interact with their patients. Patient satisfaction may be higher in patients who use the DD notepad.
Disclosures: Aaron S. Farberg, MD, and Andrew M. Lin, MD, contributed equally in every way and should be considered co‐first authors. This work was supported by a University of Michigan Fostering Innovations Grant. The authors have no conflicting financial interests.
In their seminal report Crossing the Quality Chasm, the Institute of Medicine outlined patient‐centered care as 1 of its 6 aims to improve the healthcare delivery system.[1] Patients who are more involved in their diagnosis and treatment plan are more likely to feel respected, be satisfied with their healthcare experience, and ultimately have better outcomes.[2, 3] In a study of hospitalized patients, only 42% were able to state their diagnosis at the time of discharge, suggesting that hospital providers could communicate better with patients about their hospital care.[4] Additionally, only 28% of hospitalized patients were able to list their medications, and only 37% were able to state the purpose of their medications. Although hospitals have taken great strides to improve the quality of patient care, publicly reported patient care surveys, such as the Hospital Consumer Assessment of Hospitals and Health Systems (HCAHPS), suggest that physician communication with patients could be further improved.[1, 5] Furthermore, a recent report by the Institute of Medicine stresses the need to get patients and families involved in their care.[6] Thus, hospital‐based providers should seek to enhance the quality of their communication with patients.
With greater emphasis placed on patient‐ and family‐centered care at many health systems, simple and easy‐to‐implement strategies to improve communication with patients need to be developed and tested.[7, 8] Patients who actively participate in their healthcare by asking questions of their doctor are able to control the focus of their interaction and adjust the amount of information provided.[9] Simply asking questions can have a critical impact, as 1 study found that the frequency with which patients asked questions was significantly related to the amount of information received about general and specific medical matters.[10] The notepad is a common tool for reminders and personal interactions that is used in everyday life, but has not been formalized in the hospital. We introduced Dear Doctor (DD) notes, a bedside notepad designed to prompt patient questions, with the goal of facilitating patient communication with their hospitalist physicians (Figure 1). As hospitalists provide direct and indirect care to a growing number of hospitalized patients, they are likely to be asked questions and opinions about the patients' diagnoses and plans. Furthermore, hospitalists are poised to lead institutional quality, safety, efficiency, and service improvement efforts in the inpatient setting. Becoming familiar with communication‐enhancing tools, such as the DD notes, may help hospitalists in their improvement team roles.

METHODS
Setting
We conducted a study between July 2009 and September 2009 on inpatient medical wards at a large academic medical center with 610 beds and over 44,000 annual discharges.[11] The internal medicine services served by attending physicians and residents comprise a large proportion of hospitalized patients, accounting for over 17,000 discharges per year. Each medical unit includes 32 beds.
Population
Patients over the age of 18 years admitted to a general medicine or cardiology unit and who were able to verbally communicate in English were eligible to be surveyed in the study. Patients with a length of stay <24 hours were excluded. A total of 664 patients were surveyed for inclusion in the study, 440 patients in the intervention group and 224 patients in the control group.
Intervention
The DD notepad included sample questions and informational prompts derived with input from a community focus group. The community focus group consisted of current and formerly hospitalized patients and family members who were asked by members of the study group what they thought would be important to include on a notepad provided to patients. From their answers the study team developed the DD notepad prototype. The DD notepad included 3 general categories of questions: (1) diagnosis and treatment, (2) tests and procedures, and (3) medications. To address other miscellaneous topics such as discharge and posthospital care needs, a section was designated for the patient to check off as I have a few more questions (Use the back of the sheet).
All patients admitted to the study units were intended to receive the DD notepad and pen, which were placed on the bedside table during the room change by our custodial staff. Patients who did not receive DD notepads in the intervention group during their first hospitalization day were provided with 1 by the clinical assistants working with the hospitalists. These patients did not initially receive the notepad due to logistical reasons from temporary rotating staff who were not instructed to provide the notepads. Patients were not formally prompted to use the notepad. Hospitalists, residents, and nurses on the study units were informed about the distribution of DD notes to patients on these units; however, they were not provided with any specific instructions on how they should incorporate the DD notes into their interactions with their patients. The use of the DD notepad was left to each healthcare professional's own discretion.
Members of the study team surveyed patients who had been in the hospital for a minimum of 24 hours in the intervention and control groups twice weekly. All responses were deidentified of any personal or health information. Patients were asked to rate on a scale from 1 to 5 their use of the DD notepads, their perceived value, the circumstances in which the notepads were used, and their level of satisfaction with how their physicians communicated and answered their questions (1 = no improvement, 5 = significant improvement). For control patients, questions pertaining to DD notepads were not applicable and were therefore excluded.
Statistical Analysis
The data were analyzed in an intention‐to‐treat analysis of all 440 patients in the intervention group. Intervention and control groups were compared using 2, rank sum, and Fisher exact statistical tests, with significance assigned as P < 0.05, using SPSS software version 17.0 (SPSS, Inc., Chicago, IL). Our project was approved by the University of Michigan's institutional review board.
RESULTS
Of the 440 patients surveyed in the intervention group (1 general medicine and 1 cardiology unit), 343 (78%) received the notepads in their rooms and 207 (47%) used them (Figure 2). Not every patient in the intervention group received DD notepads due to inconsistent placement of DD notepads upon every room turnover. Of the patients admitted to the control group (1 general medicine and 1 cardiology unit), 224 were surveyed. Fifty‐four percent of the 440 patients in the intervention group reported that they took notes related to their hospital care, compared to only 22% of the 224 patients in the control group (P < 0.001). Of the patients who took notes within the intervention group (n = 207), 91% of them utilized the DD notepads.

Patients in the intervention group who received and used the DD notes (n = 207) compared to patients in the control group (n = 224) were more likely to report that their questions were answered by their physicians (4.63 vs 4.45, P < 0.001). In an intention‐to‐treat analysis of all 440 patients in the intervention group, the overall satisfaction with physician communication was not significantly different between the intervention and control groups as measured on a 5‐point Likert scale (4.55 vs 4.55, P = 0.89). However, 89% of the patients in the intervention group who used the notepads felt that DD notepads either moderately or significantly improved their communication with their providers (Figure 3).

When the 207 patients who received DD notepads were asked how they used this tool, 99% of these patients used DD to write down questions, 82% to keep track of tests and procedures, and 54% indicated that their family and friends also used the notepads during the hospital stay (Table 1). Among these patients who utilized the DD notepads, 93% reported that they would use them again in the future.
Wrote Notes? (P < 0.001) (%) | Used DD? (%) | Use in Future? (%) | Frequency of Questions Answered (P < 0.001) | DD Improved Communication | Satisfied With Communication? (P = 0.89) | |
---|---|---|---|---|---|---|
| ||||||
Intervention (n = 440) | 54 | 91 | 93.2 | 4.63 | 3.76 | 4.55 |
Control (n = 224) | 22 | 4.45 | 4.55 |
Of the 97 patients in the intervention group who did not receive a DD notepad, we asked if they would use the DD notepad if they were made aware of such a tool. Of these patients, 77% agreed that they would use DD notes if they were made available in the future, 100% of them said that they would use DD to write down questions, 97% indicated that they would write notes about tests and procedures, and 88% of them believed that their families and friends would use DD notes.
DISCUSSION
As hospitals place greater emphasis and value on patient‐centered care as part of their clinical mission, it is important to develop tools to help facilitate the doctor‐patient relationship. We found that patients who were provided the Dear Doctor notepad were more satisfied that their doctors answered their questions and felt this tool enhanced their ability to communicate with their physicians. Employing the use of a familiar tool such as the notepad to remind patients about specific issues in their interactions with their providers can be a powerful intervention. Our study demonstrated that the DD notepad was widely accepted by patients, and that almost all of them would use this tool if it were made available to them in the future.
Other tools and methods to enhance the quality of communication between patients and their healthcare providers have included using whiteboards in the patients' rooms to relay the care plan to the patients, implementing bedside rounds by the healthcare team, and multidisciplinary huddling to coordinate information to the patient.[12, 13] Studies of these communication tools have shown potential to improve teamwork, interaction, and patient care. All of these have their own merit and value, and our DD notepad should be considered an adjunct to existing methods to enhance the patient care experience. A bedside tool that is familiar in form to most patients also needs to have the feature of easy access and use. Once this barrier has been removed for the patient and their family members, tools such as the DD notepad can impact the patient‐centeredness by fostering increased and better quality dialogue between the patients, their family members, and healthcare providers.
The DD notepad represents a means of communication that may have the potential to empower patients. It is possible that through question prompts, the DD notepad stimulates the patient to be an active partner with his or her healthcare team. This may enable patients to have some sense of control and accountability of their care in a setting where they would otherwise feel overwhelmed or powerless. The 3 general categories to help patients write down their questions included diagnosis, treatment plan, and medications. In the inpatient setting, where patient‐care activities can be fast paced, and patients are unable to recall some details when speaking to the healthcare team, these notes may remind the patient to write their thoughts down so that they may be remembered for a future time. In situations where patients may not know which questions to ask, the question prompts may be particularly helpful. We did not assess whether our particular question prompts were the key elements that resulted in their perceived value, or whether simply placing a blank notepad at the bedside would also have been successful. However, the specific questions were suggested by the focus groups. Enhanced communication, focusing on the patients' understanding of their condition, and the need to pursue certain diagnostic or therapeutic interventions, may help patients to be better prepared for the next course of plan. These topics of reasons for hospitalization, treatment plan, and medication changes are also important for patients to be active participants in their care, in particular as they transition from 1 site of care to the next, and their healthcare will be delivered by different providers.
There are several limitations to our study. First, this intervention was performed at a single hospital site with only 2 clinical services (general medicine, cardiology) represented in the study groups. Although we do not have any causal reasons to believe this tool would be looked upon differently by patients on other clinical services, it is possible that patients on a different clinical unit or service may view this tool as less or more useful. Second, as the patients were not randomized to intervention, but rather based on the units to which they were admitted, it is possible that other variables, such as the experience of the unit staff, the patient's condition, and housestaff‐based service versus hospitalist‐based service may have played a role in how the patients perceived the use of DD notes. Third, patients were only surveyed if they were able to verbally communicate in English. These notes may not be as useful in hospital settings to populations with language or literacy barriers. Fourth, the logistical implementation of DD notes limited our ability to deliver the DD notepads in every patient's rooms, where only 78% of the intervention group received the DD notepads. This may be the reason that we did not find that overall satisfaction with physician communication differed between intervention and control groups. Nonetheless, we performed an intention‐to‐treat analysis to minimize any biases in our analysis. Last, although our survey of patients asked about their satisfaction in using the DD note pads, we did not compare these results with those of Press‐Ganey or HCAHPS scores of patients on the intervention group versus the control group. Additionally, lack of data about type, quality, and quantity of questions asked by a control group to see if the notepads actually improved quality of questions asked is a limitation; however, we believe our outcomes of interest were most specifically evaluated through our survey questions.
DD notes show that the majority of patients who use this tool feel a modest to significant improvement in communication with their providers. Although the quality of medical care is undoubtedly the first priority, the patients' view of their care, which includes communication, is arguably just as important. An often‐forgotten goal of hospitals and clinics is to provide service excellence along with high‐quality care. Thus, it is imperative for hospitals and their care providers to not only focus on the quality and safety of the clinical care, but also be mindful of the patient's entire experience throughout their hospital stay. Many of the categories of questions asked in the HCAHPS address the patient's experience and perspectives of hospital care. Furthermore, the role of the HCAHPS survey in the Value‐Based Purchasing rules may enhance the importance of these notepads. As the results of HCAHPS are becoming more transparent and available to the public, the impact of such results will have a greater significance to the future of the hospital's clinical mission.
CONCLUSION
DD notepads are a simple, low‐cost, patient‐centered tool that can be an effective reminder for patients to ask their healthcare providers questions related to their hospital care. Utilizing a common tool such as the notepad, redesigned for the healthcare setting, can serve to help healthcare providers interact with their patients. Patient satisfaction may be higher in patients who use the DD notepad.
Disclosures: Aaron S. Farberg, MD, and Andrew M. Lin, MD, contributed equally in every way and should be considered co‐first authors. This work was supported by a University of Michigan Fostering Innovations Grant. The authors have no conflicting financial interests.
- Committee on Quality of Health Care in America, Institute of Medicine. Crossing the Quality Chasm: A New Health System for the 21st Century. Washington, DC: National Academy Press; 2001.
- An evidence base for patient‐centered cancer care: a meta‐analysis of studies of observed communication between cancer specialists and their patients. Patient Educ Couns. 2009;77(3):379–383. , , , .
- Effective physician‐patient communication and health outcomes: a review. Can Med Assoc J. 1995;152:1423–1433. .
- Patients' understanding of their treatment plans and diagnosis at discharge. Mayo Clin Proc. 2005;80(8):991–994. , .
- Patients' perception of hospital care in the United States. N Engl J Med. 2008;359:1921–1931. , , , .
- Institute of Medicine of the National Academies.Best care at lower cost: the path to continuously learning health care in America. Available at: http://www.iom.edu/Reports/2012/Best‐Care‐at‐Lower‐Cost‐The‐Path‐to‐Continuously‐Learning‐Health‐Care‐in‐America.aspx. Accessed October 5, 2012.
- An introduction to technology for patient‐centered collaborative care. J Ambul Care Manage. 2006;29:195–198. , .
- Effect on health‐related outcome of interventions to alter the interaction between patients and practitioners: a systematic review of trials. Ann Fam Med. 2004;2(6):595–608 , , , , , .
- Characteristics of physicians with participatory decision‐making styles. Ann Intern Med. 1996;124(5):497–504. , , , , .
- Information‐giving consultations: the influence of patients' communicative styles and personal characteristics. Soc Sci Med. 1991:32(5):541–548. .
- University of Michigan Health System.Patient care and University of Michigan Health System. Available at: http://www.uofmhealth.org/about%2Bumhs/about‐clinical‐care. Accessed August 31, 2012.
- It's the writing on the wall: whiteboards improve inpatient satisfaction with provider communication. Am J Med Qual. 2011;26(2):127–131 , , , et al.
- Patient whiteboards as a communication tool in the hospital setting: a survey of practices and recommendations. J Hosp Med. 2010;5(4):234–239. , , , , .
- Committee on Quality of Health Care in America, Institute of Medicine. Crossing the Quality Chasm: A New Health System for the 21st Century. Washington, DC: National Academy Press; 2001.
- An evidence base for patient‐centered cancer care: a meta‐analysis of studies of observed communication between cancer specialists and their patients. Patient Educ Couns. 2009;77(3):379–383. , , , .
- Effective physician‐patient communication and health outcomes: a review. Can Med Assoc J. 1995;152:1423–1433. .
- Patients' understanding of their treatment plans and diagnosis at discharge. Mayo Clin Proc. 2005;80(8):991–994. , .
- Patients' perception of hospital care in the United States. N Engl J Med. 2008;359:1921–1931. , , , .
- Institute of Medicine of the National Academies.Best care at lower cost: the path to continuously learning health care in America. Available at: http://www.iom.edu/Reports/2012/Best‐Care‐at‐Lower‐Cost‐The‐Path‐to‐Continuously‐Learning‐Health‐Care‐in‐America.aspx. Accessed October 5, 2012.
- An introduction to technology for patient‐centered collaborative care. J Ambul Care Manage. 2006;29:195–198. , .
- Effect on health‐related outcome of interventions to alter the interaction between patients and practitioners: a systematic review of trials. Ann Fam Med. 2004;2(6):595–608 , , , , , .
- Characteristics of physicians with participatory decision‐making styles. Ann Intern Med. 1996;124(5):497–504. , , , , .
- Information‐giving consultations: the influence of patients' communicative styles and personal characteristics. Soc Sci Med. 1991:32(5):541–548. .
- University of Michigan Health System.Patient care and University of Michigan Health System. Available at: http://www.uofmhealth.org/about%2Bumhs/about‐clinical‐care. Accessed August 31, 2012.
- It's the writing on the wall: whiteboards improve inpatient satisfaction with provider communication. Am J Med Qual. 2011;26(2):127–131 , , , et al.
- Patient whiteboards as a communication tool in the hospital setting: a survey of practices and recommendations. J Hosp Med. 2010;5(4):234–239. , , , , .
© 2013 Society of Hospital Medicine
VTE Prevention Guidelines for Inpatients
Patients hospitalized for acute medical illness have more than a 10‐fold increased risk for venous thromboembolism (VTE),[1] with an undeniably dramatic, negative impact on the lives of those afflicted, including fatal pulmonary embolism (PE), which most commonly affects patients on the medical service.[2, 3, 4] Yet estimates for the overall rate of VTE in this population are relatively low, raising questions about which subsets of medical patients warrant the risk and cost of prophylaxis.
Recently, the American College of Physicians published guidelines (ACP‐1)[5] and a supporting review[6] addressing VTE prophylaxis in nonsurgical inpatients, followed by publication of the American College of Chest Physicians (ACCP) 9th Edition of the Chest Guidelines on Antithrombotic Therapy and Prevention of Thrombosis (AT9),[7] which divides VTE prevention into 3 articles,[8, 9, 10] including 1 on nonsurgical patients.[8] Both ACP‐1 and AT9 differ significantly from the 2008 ACCP guidelines (AT8),[11] but took different approaches to methodology, risk assessment, and several other aspects of thromboprophylaxis (Table 1). This narrative review summarizes and compares these recommendations and the methods used to arrive at them, with a final section focusing on implications for improvement teams designing order sets and system changes to address VTE prophylaxis.
2008 ACCP VTE Guideline AT8 | 2012 ACCP VTE Guideline AT9 | 2011 ACP Guideline | |
---|---|---|---|
| |||
Stance on asymptomatic VTE end points | Because of the strong concordance between asymptomatic DVT and clinically important VTE, we believe that DVT detected by a sensitive screening tesis an appropriate outcome in the early assessment of new thromboprophylaxis interventions. | Use of this surrogate (asymptomatic, screening‐detected thrombosis) creates major problems in making the trade‐off between patient‐important outcomes (thrombosis and serious bleeding). | Surrogate outcomes of asymptomatic screening detected‐thrombosis should not be used. |
Who should be prophylaxed? | 6.0.0: For acutely ill medical patients admitted to hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, including active cancer, previous VTE, sepsis, neurologic disease, or inflammatory bowel disease, we recommend thromboprophylaxis with LMWH (1A), UFH (1A), or fondaparinux (1A). | 2.3: For acutely ill hospitalized medical patients at increased risk for thrombosis, we recommend anticoagulant thromboprophylaxis, with LMWH, UFH bid, UFH tid, or fondaparinux (1B). | ACP recommends pharmacologic prophylaxis with heparin or a related drug for venous thromboembolism in medical (including stroke) patients unless the assessed risk for bleeding outweighs the likely benefits (grade: strong recommendation, moderate‐quality evidence). |
2.4: For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic or mechanical prophylaxis. (1B) | |||
Choice of anticoagulant prophylaxis | There is no compelling evidence that UFH should be administered three times daily in preference to twice daily in medical patients, although these two regimens have never been directly compared. | In choosing the specific anticoagulant drug to be used for pharmacoprophylaxis, choices should be based on patient preference, compliance, and ease of administration (eg, daily vs bid vs tid dosing), as well as on local factors affecting acquisition costs. | [T]he choice of agent for prophylaxis of VTE should be based on ease of use, adverse effect profile, and cost of medication. |
No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | |
Mechanical prophylaxis | 1.4.3.1: We recommend that mechanical methods of prophylaxis be used primarily in patients at high risk of bleeding (grade 1A), or possibly as an adjunct to anticoagulant‐based thromboprophylaxis (grade 2A). | 2.7.2: For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or at high risk for major bleeding, we suggest the optimal use of mechanical thromboprophylaxis with GCS (grade 2C) or IPC (grade 2C). | ACP recommends against the use of mechanical prophylaxis with graduated compression stockings for prevention of venous thromboembolism (grade: strong recommendation, moderate‐quality evidence). |
No strong evidence for IPC vs GCS | |||
Duration | [T]he optimal duration of thromboprophylaxis remains unclear. To the end of hospitalization for most patients. | 2.8: [W]e suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (2B). | The optimal duration of heparin prophylaxis is uncertain. |
Risk Stratification | The approach of individual prophylaxis prescribing based on formal RAMs is not used routinely by most clinicians because it has not been adequately validated and is cumbersome. Individual RAMs may not be worth the effort, because there are only a limited number of thromboprophylaxis options, and one of the principles of effective thromboprophylaxis is to reduce complexity in decision making. | (Noncritical care) No formal risk assessment recommendation. Padua point‐based model is inherent in definitions of baseline VTE risk. | ACP does not support the application of performance measures in medical (including stroke) patients that promotes universal venous thromboembolism prophylaxis regardless of risk. |
Another approach involves implementation of group‐specific thromboprophylaxis routinely for all patients who belong to each of the major target groups. We support this approach. | There are no validated risk assessment models to stratify VTE risk in critically ill patients. | Many risk assessment tools are available for estimating thromboembolism risk, but the current evidence is insufficient to recommend a validated tool. | |
[T]he decision is best left to physician judgment, and performance measures targeting all patients are inappropriate. |
WHY ARE THE NEW GUIDELINES DIFFERENT?
Major randomized controlled trials (RCTs)[12, 13, 14] of thromboprophylaxis used routine deep vein thrombosis (DVT) surveillance and included both symptomatic (S‐VTE) and asymptomatic VTE (A‐VTE) end points. These studies consistently demonstrated 44% to 63% reductions in VTE without increases in major bleeding.[11] Because of the strong relationship between A‐VTE and S‐VTE outcomes, and a paucity of studies using only S‐VTE outcomes, AT8 judged that A‐VTE outcomes were valid to include, whereas the new guidelines reject the use of asymptomatic VTE end points.[5, 8, 15] To minimize financial and intellectual conflicts of interest, AT9 also used methodologists rather than VTE experts as topic editors, excluded conflicted experts from voting on recommendations, and attempted to estimate patient values and preferences.[15] As a result, AT9 makes fewer strong recommendations (182 1A recommendations in 2008, but only 29 in 2012), replacing them with weak suggestions.
WHAT DO THE NEW GUIDELINES RECOMMEND?
AT8 recommended anticoagulant prophylaxis for acutely ill medical inpatients with known risk factors, but did not recommend routine thromboprophylaxis. However, because of well‐known problems with underprophylaxis,[16, 17, 18, 19] particularly in medical patients, the low risk of bleeding, and difficulties with explicitly defining low‐risk patients, many discounted the need for VTE risk stratification.
Both new guidelines recommend prophylaxis for many nonsurgical patients, but discourage routine thromboprophylaxis for nonsurgical inpatients. AT9 specifically recommends against any thromboprophylaxis for low‐risk medical inpatients, implying that many nonsurgical, non‐critical care patients belong in this category, citing lower estimates of benefit, lower estimates of VTE risk, and potential bleeding risks.
The guidelines[5, 8] agree that, when indicated and absent contraindications, anticoagulant prophylaxis is preferred over mechanical prophylaxis, and agree there is insufficient evidence to recommend 1 anticoagulant over another.
For patients at risk of both VTE and bleeding, ACP‐1 states that intermittent pneumatic compression (IPC) devices are a reasonable option, given the evidence showing benefit in surgical patients. However, ACP‐1 recommends against graduated compression stockings (GCS) in nonsurgical patients based on a meta‐analysis dominated by the CLOTS‐1 (Clots in Legs Or sTockings after Stroke) trial, which found that thigh‐high GCS increased the risk of skin breakdown without reducing VTE[20] in immobilized stroke patients. AT9 does not recommend against GCS for patients facing bleeding and VTE risk. AT9 notes the hazards of generalizing results from stroke patients, and also considers the somewhat contradictory results from the CLOTS‐2 trial in stroke patients, which found a lower rate of VTE with thigh‐high GCS than with knee‐high GCS.[21] AT9 designates a recommendation of 2C for either IPC devices or thigh‐high GCS for those at VTE risk when anticoagulants are contraindicated.
Combination mechanical‐pharmacologic prophylaxis has proven superior in some surgical populations, and many hospitals use combined prophylaxis in high‐risk medical patients. However, combination prophylaxis has not been studied in this population. ACP‐1 does not comment on the practice; AT9 does not recommend for or against it. Institutions that use combination prophylaxis should be aware that although it may seem logical to extrapolate estimates of benefit seen in selected surgical patients, this is not a recommended practice.
RCTs for thromboprophylaxis in nonsurgical inpatients provided prophylaxis for 6 to 21 days. Neither ACP‐1 or AT9 recommend routinely extending prophylaxis beyond the hospital stay, citing an RCT[22] in which the benefit of extended duration low molecular weight heparin was limited to selected subsets of patients and offset by bleeding complications. AT9 suggests prophylaxis for 6 to 21 days, until full mobility is restored, or until dischargewhichever comes first.[8] However, we know of no study that establishes a mobility level at which prophylaxis can be safely discontinued, especially in inpatients with multiple risk factors.
ESTIMATING RISK AND BENEFIT OF PROPHYLAXIS AND LIMITATIONS OF METHODS
Calculating risk/benefit ratios for thromboprophylaxis requires estimates of baseline VTE and bleeding risks, and estimates of the impact of prophylaxis on those baseline risks. Methods to estimate the impact of prophylaxis on S‐VTE from studies relying on A‐VTE all have limitations, as acknowledged by the AT9 introduction.[15]
The ACP‐1 review found the only significant effect of prophylaxis on medical inpatients was a modest reduction in PE and a modest increase in total bleeding events, without effects on major bleeding, DVT, or mortality.[6] The authors summarized the findings as indicative of little or no net benefit for the medical population as a whole. The ACP‐1 review derives estimates of S‐VTE risk, bleeding, and mortality from control (baseline) and interventional arms of RCTs that used routine VTE screening, and included A‐VTE end points. The baseline risk of VTE could potentially be overestimated, because the populations in the trials are not representative of the entire medical population.
On the other hand, pooling trials with screening‐detected VTE to estimate S‐VTE outcomes is a questionable practice that may falsely lower estimates of VTE prophylaxis benefit. Screening‐detected VTE may be treated or declared a study end point before it becomes symptomatic. MEDENOX (Medical Patients With Enoxaparin) is an illustrative example.[12] The 263 placebo recipients suffered 37 A‐VTEs and 4 S‐VTEs. The 272 enoxaparin recipients suffered 17 A‐VTEs and 3 S‐VTEs. Patients at the highest risk of S‐VTE were counted as reaching an end point before they could develop symptoms; this happened more than twice as often in the placebo arm. This decreases both estimates of baseline VTE risk and the measured benefit of prophylaxis for S‐VTE. Screening could conceivably reduce measured effects on mortality as well, because patients begin VTE therapy earlier. Per ACP‐1, the estimated risk for DVT is lower than for PE, running counter to literature experience[8, 16] and raising issues of face validity. The ACP‐1 review accepts all original definitions of major bleeding, including a 2 g/dL drop in hemoglobin,[12] which commonly occurs without any bleeding or clinical consequence, and bleeding events were ascribed to heparins up to 120 days after randomization, long after they could have been responsible.
Previous meta‐analyses of thromboprophylaxis studies[23, 24] shared many of these same limitations, but did not ascribe bleeding complications to heparins for this extended duration, and had point estimates that suggested a larger impact from prophylaxis than ACP‐1. Dentali et al., for example, showed statistically significant impact on PE (relative risk [RR] 0.43), fatal PE (RR 0.38), and a nearly statistically significant large impact on DVT (RR 0.47, 95% confidence interval [CI]: 0.22‐1.00),[24] whereas ACP‐1 estimated a smaller significant impact on PE (RR 0.69), no significant difference in fatal PE, and a much smaller estimate of the impact on DVT (RR 0.78, 95% CI: 0.45‐1.35) (Table 2).
Baseline Risk | Relative Effect (95% CI) | Absolute Effect per 1000 Patients Treated (95% CI) | |
---|---|---|---|
| |||
ACP guideline review (Lederle), UFH or LMWH vs placebo/no treatment, medical patients | |||
Mortality | 6.6 | OR 0.94 (0.84‐1.04) | 4 fewer (11 fewer to 3 more) |
Major bleeding | 0.25 | OR 1.49 (0.91‐2.43) | 1 more (no effect to 3 more) |
Symptomatic DVT | 0.96 | OR 0.78 (0.45‐1.35) | 2 fewer (6 fewer to 4 more) |
PE | 1.2 | OR 0.69 (0.52‐0.90) | 4 fewer (6 fewer to 1 fewer) |
Fatal PE | 0.30 | OR 0.77 (0.43‐1.37) | 1 fewer (2 fewer to 1 more) |
ACCP AT9 (Kahn), non‐critical care medical inpatients, anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Mortality | 4.5 | OR 0.97 (0.79‐1.19) | 1 fewer (9 fewer to 8 more) |
Major bleeding | 0.40 | OR 1.32 (0.73‐2.37) | 1 more (1 fewer to 6 more) |
Thrombocytopenia | 0.13 | OR 0.92 (0.54‐1.53) | 1 fewer (6 fewer to 7 more) |
Symptomatic DVT | |||
Padua score <4 | 0.2 | RR 0.47 (0.22‐1) | 1 fewer (1 fewer to no effect) |
Padua score 4 | 6.7 | 34 fewer (51 fewer to no effect) | |
ACCP AT9 (Kahn) non‐critical care medical inpatients, Anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Nonfatal PE | |||
Padua score 4 | 0.2 | RR 0.61 (0.23‐1.67) | 1 fewer (1 fewer to 1 more) |
Padua score 4 | 3.9 | 15 fewer (30 fewer to 36 more) | |
Fatal PE | 0.4 | RR 0.41 (0.22‐0.76) | 2 fewer (1 fewer to 3 fewer) |
ACCP AT9 (Kahn), critical care medical inpatients, any heparin (LMWH, UFH) vs placebo/no treatment) | |||
Mortality | 9.4 | RR 1.01 (0.04‐2.57) | 1 more (56 fewer to 148 more) |
Major bleeding | 2.7 | RR 2.09 (0.54‐8.16) | 29 more (12 fewer to 190 more) |
Symptomatic DVT | 5.8 | RR 0.86 (0.59‐1.25) | 4 fewer (12 fewer to 8 more) |
Pulmonary embolus | 4.2 | RR, 0.73 (0.26‐2.11) | 11 fewer (31 fewer to 47 more) |
AT9 used a variety of methods to estimate each component of the risk/benefit equation. Critical care and non‐critical care estimates were generated independently, but because of limited data, the critical care estimates were highly imprecise. In non‐critical care patients, as in ACP‐1, treatment effects were estimated from RCTs that routinely screened for A‐VTE, and they adapted the Dentali et al. estimate of DVT risk reduction. The baseline risk for bleeding and mortality were derived from the control population of the same meta‐analysis.[24]
Using a novel approach, AT9 estimated baseline nonsurgical VTE risk from a prospective observational cohort study of 1180 medical inpatients divided into high‐ and low‐risk groups by a point‐scoring system.[25] Deriving risk estimates from an observational cohort has theoretical advantages. Many patients did not receive prophylaxis, allowing for unadjusted risk estimates; they represented a cross‐section of medical inpatients rather than a selected trial population, and risk estimates were not reduced by the culling of screen‐detected A‐VTE.
The Padua risk‐assessment model (RAM) (Table 3) defines high VTE risk as a cumulative score 4. There were 60.3% of patients at low risk and 39.7% at high risk using this threshold. Among unprophylaxed patients, VTE occurred in 11% of high‐risk patients versus 0.3% of low‐risk patients (hazard ratio 32.0, 95% CI: 4.1251.0).
Baseline Features | Score |
---|---|
| |
Active cancer* | 3 |
Previous VTE (excluding superficial thrombosis) | 3 |
Reduced mobility | 3 |
Already known thrombophilic condition | 3 |
Recent (1 month) trauma and/or surgery | 2 |
Elderly age (70 years) | 1 |
Heart and/or respiratory failure | 1 |
Acute myocardial infarction or stroke | 1 |
Acute infection and/or rheumatologic disorder | 1 |
Obesity (BMI 30) | 1 |
Ongoing hormonal treatment | 1 |
PADUA: A CLOSER LOOK
In the Padua study, 60% of the population appeared to be at such low risk for VTE that prophylaxis would seem unnecessary, but closer scrutiny should raise concern about generalizing these results. Of the 711 low‐risk patients, <1% were immobile, only 6% had cancer, 6% were obese, and only 12% had any acute infection or inflammatory condition, yet their mean length of stay was 7.9 days. These characteristics do not apply to 60% of American inpatients. Furthermore, 964 of 2208 eligible patients (44%) were excluded because they required therapeutic anticoagulation.[25]
Correspondence with the authors revealed that the 2 PEs in patients with Padua scores 4 occurred among 192 patients with a risk score of 3 (Figure 1), a 1% (2/192) risk of PE. This is a very small sample, and the true risk of VTE for medical inpatients with a risk score of 3 may be lower or significantly higher. In the Padua population, a risk score of 3 equated to a VTE risk of 6.9%, whereas those with a score of 0 to 2 had no VTE. For those adapting the Padua model, careful consideration of using a cutoff of 3, versus 4, is warranted.

IMPLICATIONS FOR VTE PROTOCOL IMPLEMENTATION AND IMPROVEMENT TEAMS
AT9 and ACP‐1 sought to focus on S‐VTE, remove bias from recommendations, and highlight potential risks of unnecessary prophylaxis in low‐risk patients. They have largely succeeded in these important goals. However, the complexity of the new guidelines and lack of consensus about VTE risk assessment pose significant challenges to improvement teams tasked with implementing the guidelines in real‐world settings.
CHOOSING A VTE RAM
The fundamental question is: How can hospitals assess VTE risk, assure adequate prophylaxis for patients who need it, while minimizing excess prophylaxis, in a practical, efficient way?
Approach 1: Opt Out Approach
Both guidelines discourage universal prophylaxis for inpatients without contraindications unless the physician opts out. Although the simplicity of this approach is appealing, the low rate of VTE in a substantial segment of the medical inpatient population and known risks of thromboprophylaxis make this strategy suboptimal.
Approach 2: No VTE RAM
ACP‐1 notes that evidence is not sufficient to recommend 1 RAM over another, and essentially advises leaving prophylaxis decisions up to an individual physician's judgment. Although the evidence may not prove which system is best, prophylaxis reliability is dismal when there is no system or when hospitals offer prophylaxis options without guidance.[26, 27] Widespread, well‐documented underprophylaxis[16, 17, 18, 19] is largely the result of relying on unguided physician judgment and relatively passive interventions like educational sessions and pocket cards.[8] This approach also deprives improvement teams of standard definitions of VTE risk, bleeding risk, and adequate prophylaxis necessary to measure and improve VTE prophylaxis. Because of significant gray areas in the literature and varied infrastructure, institutions will not implement identical VTE prevention programs, but institutional standardization remains a cornerstone of improvement.
Approach 3: Buckets of Risk
The AT8 approach to risk assessment was to place patients into VTE risk groups described in the text, rather than have an individualized point‐scoring system.[11] These assessments can be made in seconds with high levels of interobserver agreement, implemented without undue effort, and spur high levels of compliance.[28, 29] Most importantly, implementation was associated with a 40% reduction in hospital‐associated VTE (RR 0.69, 95% CI: 0.470.79) without detectable increases in bleeding or heparin‐induced thrombocytopenia. Although this strategy has not been tested in randomized trials, it has been replicated in multiple real‐world settings that avoid concerns about generalizability due to imperfect trial populations.[28, 30]
The most popular bucket model in common use, derived from a table in the AT8 guidelines, is similar to models presented in UK National Institute for Health and Care Excellence guidelines for medical inpatients.[31] These models are potentially less precise than point‐based systems, but offer simplicity, ease of use, and improved physician acceptance, and thus may be more effective than point‐based models in settings without advanced clinical decision support. The models are flexible to reflect greater or lesser degrees of aggressiveness in defining risk categories, and can be used to approximate some point‐based systems.
Approach 4: Individualized Point‐Based RAM
AT9 authors used the Padua VTE RAM to define low‐ and high‐risk patients for VTE in their recommendation for medical inpatients. The Padua model appears relatively simple, but it does require calculations, and there is a paucity of data for implementation experience with it. As mentioned above, if teams use the Padua model, the optimal cutoff (3 vs 4) for recommending prophylaxis is uncertain, and both should be considered.
The Caprini point‐based system is not mentioned in the guideline for thromboprophylaxis in medical inpatients, but in our collaborative improvement experience, it is perhaps the most commonly used point‐based model for medical inpatients.[28, 30] It is also embedded in AT9 recommendations for prophylaxis in the nonorthopedic surgical population,[9] and thus is tempting to use for both medical and surgical patients. There are several caveats to those considering the use of these more complex point‐based models. Complex point‐based RAM suffer from poor interobserver agreement.[32] They have also had limited ability to exclude low‐risk patients from prophylaxis in validation studies,[33] and have not been tested extensively in medical populations. Although AT9 considers the Caprini RAM relatively easy to use,[9] our experience in collaboratives suggests that for many hospitals, the model is too complex to be used reliably.[28, 30] Clinicians often simply bypass the clinical decision support offered in the tool, rather than checking off all risk factors, adding up the point total, and identifying the appropriate prophylaxis choices based on the point total.[28] Other point‐based RAM (reviewed elsewhere[34, 35, 36]) pose similar implementation challenges.
On the other hand, centers with more sophisticated clinical decision support and a strong improvement framework can overcome some of these challenges to get good results with complex point‐based models. A forcing function can ensure that practitioners complete all risk‐assessment tasks. Providers can check off the VTE risk factors and bleeding risk factors on 1 screen, and several factors like age, body mass index, and renal function can be autopopulated. Instead of asking the provider to add up points, the combination of answers checked off on the first screen can drive behind‐the‐scenes calculations and seamlessly lead providers to prophylaxis choices appropriate for that combination of VTE and bleeding risks. Customized models can be designed for a wide variety of services. Similar strategies can ease adaption with more complex qualitative models as well.[37]
BOTTOM LINE IN CHOOSING A VTE RAM
Many medical inpatients are at high risk for VTE, but others are not at sufficient risk to warrant prophylaxis. VTE risk assessment should be embedded in admission, transfer, and perioperative order sets and may need a hard stop to insure completion. There is a trend to favor individualized point‐based models over models that place patients in groups of risk, but evidence is insufficient to recommend 1 type of RAM over another, and more complex point‐based models often require extensive local customization and algorithmic clinical decision support to effectively implement them. Centers without advanced capability may find the bucket models more effective. We urge improvement teams to trial their RAM with common patient case scenarios, and to make a choice based on an effort‐benefit analysis, feedback from their clinicians, and the level of customization in clinical decision support available to them.
OTHER IMPLEMENTATION STRATEGIES
VTE and bleeding risk change during hospitalization. We have used ongoing daily surveillance and measurement of patients on no prophylaxis to prompt concurrent intervention (ie, measure‐vention) to increase prophylaxis for patients at risk.[28] Improvement teams should focus not only on increasing prophylaxis for those at risk, but should also use measure‐vention, checklists, or other techniques to identify low‐risk (eg, ambulating) patients for cessation of overly aggressive prophylaxis. Efforts to improve early progressive ambulation, limit central venous catheters to those who truly need them, and improve adherence to mechanical prophylaxis can also reduce VTE, as well as benefitting patient populations in other ways.
We recognize there are several approaches to close the implementation gap in delivering thromboprophylaxis judiciously but reliably, and encourage research and publication of varied strategies. Last, we hope efforts to limit unnecessary prophylaxis and challenges inherent in implementing new and complex guidelines do not increase the morbidity and mortality of hospital‐acquired VTE, by derailing the delivery of prophylaxis to those in whom the benefits outweigh the risks.
Disclosures: Dr. Merli has conducted research for Johnson & Johnson, Bristol Myers Squibb, and Portala Scientific and has been a consultant for Johnson & Johnson and Bristol Myers Squibb.
- US Department of Health and Human Services. Surgeon General's call to action to prevent deep vein thrombosis and pulmonary embolism. 2008. Available at: http://www.surgeongeneral.gov/topics/deepvein/index.html. Accessed January 29, 2013.
- Incidence of venous thromboembolism in hospitalized patients vs. community residents. Mayo Clin Proc. 2001;76:1102–1110. , , , et al.
- Risk factors for deep vein thrombosis and pulmonary embolism: a population‐based case‐control study. Arch Intern Med. 2000;160(6):809–815. , , , , , .
- New onset of venous thromboembolism among hospitalized patients at Brigham and Women's Hospital is caused more often by prophylaxis failure than by withholding treatment. Chest. 2000;118(6):1680–1684. , , .
- venous thromboembolism prophylaxis in hospitalized patients: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2011;155(9):625–632. , , , , .
- Venous thromboembolism prophylaxis in hospitalized medical patients and those with stroke: a background review for an American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2011;155(9):602–615. , , , .
- Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):e419S–e494S. , , , et al.
- Prevention of VTE in nonsurgical patients. Chest. 2012;141(2 suppl):e195S–e226S. , , , et al.
- Prevention of VTE in nonorthopedic surgical patients. Chest. 2012;141(2 suppl):e227S–e277S. , , , et al.
- Prevention of VTE in orthopedic surgery patients. Chest. 2012;141(2 suppl):e278S–e325S. , , , et al.
- Prevention of venous thromboembolism. Chest. 2008;133(6 suppl):381S–453S. , , , et al.
- A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. Prophylaxis in Medical Patients with Enoxaparin Study Group. N Engl J Med. 1999;341(11):793–800. , , , et al.
- Randomized, placebo‐controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. Circulation. 2004;110(7):874–879. , , , et al.
- Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial. BMJ. 2006;332(7537):325–329. , , , et al.
- Introduction to the ninth edition: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):48S–52S. , , , , , .
- The outcome after treatment of venous thromboembolism is different in surgical and acutely ill medical patients. Findings from the RIETE registry. J Thromb Haemost. 2004;2:1892–1898. , , , et al.
- Venous thromboembolism prophylaxis in acutely ill hospitalized medical patients: findings from the International Medical Prevention Registry on Venous Thromboembolism. Chest. 2007;132(3):936–945. , , , et al.
- Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross‐sectional study. Lancet. 2008;371(9610):387–394. , , , et al.
- ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in hospitalised medically ill patients. The ENDORSE Global Survey. Thromb Haemost. 2010;103(4):736–748. , , , et al.;
- CLOTS Trials Collaboration. Effectiveness of thigh‐length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomized controlled trial. Lancet. 2009;373(9679):1958–1965. , , , et al;
- CLOTS (Clots in Legs Or sTockings after Stroke) Trial Collaboration. Thigh‐length versus below‐knee stockings for deep venous thrombosis prophylaxis after stroke: a randomized trial. Ann Intern Med. 2010;153(9):553–562.
- Extended‐duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility: a randomized trial. Ann Intern Med. 2010;153:8–18. , , , et al.
- Pharmacological venous thromboembolism prophylaxis in hospitalized medical patients: a meta‐analysis of randomized controlled trials. Arch Intern Med. 2007;167(1)476–486. , , , , .
- Meta‐analysis: anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients. Ann Intern Med. 2007; 46(4):278–288. , , , , .
- A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score. J Thromb Haemost. 2010;8(11):2450–2457. , , , et al.
- Medical admission order sets to improve deep vein thrombosis prophylaxis rates and other outcomes. J Hosp Med. 2009;4(2):81–89. , , , .
- Medical admission order sets to improve deep vein thrombosis prevention: a model for others or a prescription for mediocrity? J Hosp Med. 2009;4(2):77–80. .
- Designing and implementing effective VTE prevention protocols: lessons from collaboratives. J Thromb Thrombolysis. 2010;29(2):159–166. , .
- Optimizing prevention of hospital acquired venous thromboembolism: prospective validation of a VTE risk assessment model. J Hosp Med. 2010;5(1):10–18. , , , et al.
- 2011 John M. Eisenberg Patient Safety and Quality Awards. Mentored implementation: building leaders and achieving results through a collaborative improvement model. Innovation in patient safety and quality at the national level. Jt Comm J Qual Patient Saf. 2012;38(7):301–310. , , , et al.
- NHS National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. NICE Clinical Guideline 92. 2010. Available at: http://www.nice.org.uk/guidance/CG92. Accessed April 18, 2013.
- Reliability of a point‐based VTE risk assessment tool in the hands of medical residents. J Hosp Med. 2011;6:195–201. , , , , .
- A validation of a retrospective venous thromboembolism risk scoring method. Ann Surg. 2010;251(2):344–350. , , , , , .
- Risk assessment models for thromboprophylaxis of medical patients. Thromb Res. 2012;129:127–132. , , , .
- Risk‐assessment models for predicting venous thromboembolism among hospitalized non‐surgical patients: a systematic review. J Thromb Thrombolysis. 2013;35:67–80. , , , , .
- The use of weighted and scored risk assessment models for venous thromboembolism. Thromb Haemost. 2012;108(6):1072–1076. , , .
- Lessons from the Johns Hopkins Multi‐Disciplinary Venous Thromboembolism (VTE) Prevention Collaborative. BMJ. 2012;344:e3935. , , , et al.
Patients hospitalized for acute medical illness have more than a 10‐fold increased risk for venous thromboembolism (VTE),[1] with an undeniably dramatic, negative impact on the lives of those afflicted, including fatal pulmonary embolism (PE), which most commonly affects patients on the medical service.[2, 3, 4] Yet estimates for the overall rate of VTE in this population are relatively low, raising questions about which subsets of medical patients warrant the risk and cost of prophylaxis.
Recently, the American College of Physicians published guidelines (ACP‐1)[5] and a supporting review[6] addressing VTE prophylaxis in nonsurgical inpatients, followed by publication of the American College of Chest Physicians (ACCP) 9th Edition of the Chest Guidelines on Antithrombotic Therapy and Prevention of Thrombosis (AT9),[7] which divides VTE prevention into 3 articles,[8, 9, 10] including 1 on nonsurgical patients.[8] Both ACP‐1 and AT9 differ significantly from the 2008 ACCP guidelines (AT8),[11] but took different approaches to methodology, risk assessment, and several other aspects of thromboprophylaxis (Table 1). This narrative review summarizes and compares these recommendations and the methods used to arrive at them, with a final section focusing on implications for improvement teams designing order sets and system changes to address VTE prophylaxis.
2008 ACCP VTE Guideline AT8 | 2012 ACCP VTE Guideline AT9 | 2011 ACP Guideline | |
---|---|---|---|
| |||
Stance on asymptomatic VTE end points | Because of the strong concordance between asymptomatic DVT and clinically important VTE, we believe that DVT detected by a sensitive screening tesis an appropriate outcome in the early assessment of new thromboprophylaxis interventions. | Use of this surrogate (asymptomatic, screening‐detected thrombosis) creates major problems in making the trade‐off between patient‐important outcomes (thrombosis and serious bleeding). | Surrogate outcomes of asymptomatic screening detected‐thrombosis should not be used. |
Who should be prophylaxed? | 6.0.0: For acutely ill medical patients admitted to hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, including active cancer, previous VTE, sepsis, neurologic disease, or inflammatory bowel disease, we recommend thromboprophylaxis with LMWH (1A), UFH (1A), or fondaparinux (1A). | 2.3: For acutely ill hospitalized medical patients at increased risk for thrombosis, we recommend anticoagulant thromboprophylaxis, with LMWH, UFH bid, UFH tid, or fondaparinux (1B). | ACP recommends pharmacologic prophylaxis with heparin or a related drug for venous thromboembolism in medical (including stroke) patients unless the assessed risk for bleeding outweighs the likely benefits (grade: strong recommendation, moderate‐quality evidence). |
2.4: For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic or mechanical prophylaxis. (1B) | |||
Choice of anticoagulant prophylaxis | There is no compelling evidence that UFH should be administered three times daily in preference to twice daily in medical patients, although these two regimens have never been directly compared. | In choosing the specific anticoagulant drug to be used for pharmacoprophylaxis, choices should be based on patient preference, compliance, and ease of administration (eg, daily vs bid vs tid dosing), as well as on local factors affecting acquisition costs. | [T]he choice of agent for prophylaxis of VTE should be based on ease of use, adverse effect profile, and cost of medication. |
No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | |
Mechanical prophylaxis | 1.4.3.1: We recommend that mechanical methods of prophylaxis be used primarily in patients at high risk of bleeding (grade 1A), or possibly as an adjunct to anticoagulant‐based thromboprophylaxis (grade 2A). | 2.7.2: For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or at high risk for major bleeding, we suggest the optimal use of mechanical thromboprophylaxis with GCS (grade 2C) or IPC (grade 2C). | ACP recommends against the use of mechanical prophylaxis with graduated compression stockings for prevention of venous thromboembolism (grade: strong recommendation, moderate‐quality evidence). |
No strong evidence for IPC vs GCS | |||
Duration | [T]he optimal duration of thromboprophylaxis remains unclear. To the end of hospitalization for most patients. | 2.8: [W]e suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (2B). | The optimal duration of heparin prophylaxis is uncertain. |
Risk Stratification | The approach of individual prophylaxis prescribing based on formal RAMs is not used routinely by most clinicians because it has not been adequately validated and is cumbersome. Individual RAMs may not be worth the effort, because there are only a limited number of thromboprophylaxis options, and one of the principles of effective thromboprophylaxis is to reduce complexity in decision making. | (Noncritical care) No formal risk assessment recommendation. Padua point‐based model is inherent in definitions of baseline VTE risk. | ACP does not support the application of performance measures in medical (including stroke) patients that promotes universal venous thromboembolism prophylaxis regardless of risk. |
Another approach involves implementation of group‐specific thromboprophylaxis routinely for all patients who belong to each of the major target groups. We support this approach. | There are no validated risk assessment models to stratify VTE risk in critically ill patients. | Many risk assessment tools are available for estimating thromboembolism risk, but the current evidence is insufficient to recommend a validated tool. | |
[T]he decision is best left to physician judgment, and performance measures targeting all patients are inappropriate. |
WHY ARE THE NEW GUIDELINES DIFFERENT?
Major randomized controlled trials (RCTs)[12, 13, 14] of thromboprophylaxis used routine deep vein thrombosis (DVT) surveillance and included both symptomatic (S‐VTE) and asymptomatic VTE (A‐VTE) end points. These studies consistently demonstrated 44% to 63% reductions in VTE without increases in major bleeding.[11] Because of the strong relationship between A‐VTE and S‐VTE outcomes, and a paucity of studies using only S‐VTE outcomes, AT8 judged that A‐VTE outcomes were valid to include, whereas the new guidelines reject the use of asymptomatic VTE end points.[5, 8, 15] To minimize financial and intellectual conflicts of interest, AT9 also used methodologists rather than VTE experts as topic editors, excluded conflicted experts from voting on recommendations, and attempted to estimate patient values and preferences.[15] As a result, AT9 makes fewer strong recommendations (182 1A recommendations in 2008, but only 29 in 2012), replacing them with weak suggestions.
WHAT DO THE NEW GUIDELINES RECOMMEND?
AT8 recommended anticoagulant prophylaxis for acutely ill medical inpatients with known risk factors, but did not recommend routine thromboprophylaxis. However, because of well‐known problems with underprophylaxis,[16, 17, 18, 19] particularly in medical patients, the low risk of bleeding, and difficulties with explicitly defining low‐risk patients, many discounted the need for VTE risk stratification.
Both new guidelines recommend prophylaxis for many nonsurgical patients, but discourage routine thromboprophylaxis for nonsurgical inpatients. AT9 specifically recommends against any thromboprophylaxis for low‐risk medical inpatients, implying that many nonsurgical, non‐critical care patients belong in this category, citing lower estimates of benefit, lower estimates of VTE risk, and potential bleeding risks.
The guidelines[5, 8] agree that, when indicated and absent contraindications, anticoagulant prophylaxis is preferred over mechanical prophylaxis, and agree there is insufficient evidence to recommend 1 anticoagulant over another.
For patients at risk of both VTE and bleeding, ACP‐1 states that intermittent pneumatic compression (IPC) devices are a reasonable option, given the evidence showing benefit in surgical patients. However, ACP‐1 recommends against graduated compression stockings (GCS) in nonsurgical patients based on a meta‐analysis dominated by the CLOTS‐1 (Clots in Legs Or sTockings after Stroke) trial, which found that thigh‐high GCS increased the risk of skin breakdown without reducing VTE[20] in immobilized stroke patients. AT9 does not recommend against GCS for patients facing bleeding and VTE risk. AT9 notes the hazards of generalizing results from stroke patients, and also considers the somewhat contradictory results from the CLOTS‐2 trial in stroke patients, which found a lower rate of VTE with thigh‐high GCS than with knee‐high GCS.[21] AT9 designates a recommendation of 2C for either IPC devices or thigh‐high GCS for those at VTE risk when anticoagulants are contraindicated.
Combination mechanical‐pharmacologic prophylaxis has proven superior in some surgical populations, and many hospitals use combined prophylaxis in high‐risk medical patients. However, combination prophylaxis has not been studied in this population. ACP‐1 does not comment on the practice; AT9 does not recommend for or against it. Institutions that use combination prophylaxis should be aware that although it may seem logical to extrapolate estimates of benefit seen in selected surgical patients, this is not a recommended practice.
RCTs for thromboprophylaxis in nonsurgical inpatients provided prophylaxis for 6 to 21 days. Neither ACP‐1 or AT9 recommend routinely extending prophylaxis beyond the hospital stay, citing an RCT[22] in which the benefit of extended duration low molecular weight heparin was limited to selected subsets of patients and offset by bleeding complications. AT9 suggests prophylaxis for 6 to 21 days, until full mobility is restored, or until dischargewhichever comes first.[8] However, we know of no study that establishes a mobility level at which prophylaxis can be safely discontinued, especially in inpatients with multiple risk factors.
ESTIMATING RISK AND BENEFIT OF PROPHYLAXIS AND LIMITATIONS OF METHODS
Calculating risk/benefit ratios for thromboprophylaxis requires estimates of baseline VTE and bleeding risks, and estimates of the impact of prophylaxis on those baseline risks. Methods to estimate the impact of prophylaxis on S‐VTE from studies relying on A‐VTE all have limitations, as acknowledged by the AT9 introduction.[15]
The ACP‐1 review found the only significant effect of prophylaxis on medical inpatients was a modest reduction in PE and a modest increase in total bleeding events, without effects on major bleeding, DVT, or mortality.[6] The authors summarized the findings as indicative of little or no net benefit for the medical population as a whole. The ACP‐1 review derives estimates of S‐VTE risk, bleeding, and mortality from control (baseline) and interventional arms of RCTs that used routine VTE screening, and included A‐VTE end points. The baseline risk of VTE could potentially be overestimated, because the populations in the trials are not representative of the entire medical population.
On the other hand, pooling trials with screening‐detected VTE to estimate S‐VTE outcomes is a questionable practice that may falsely lower estimates of VTE prophylaxis benefit. Screening‐detected VTE may be treated or declared a study end point before it becomes symptomatic. MEDENOX (Medical Patients With Enoxaparin) is an illustrative example.[12] The 263 placebo recipients suffered 37 A‐VTEs and 4 S‐VTEs. The 272 enoxaparin recipients suffered 17 A‐VTEs and 3 S‐VTEs. Patients at the highest risk of S‐VTE were counted as reaching an end point before they could develop symptoms; this happened more than twice as often in the placebo arm. This decreases both estimates of baseline VTE risk and the measured benefit of prophylaxis for S‐VTE. Screening could conceivably reduce measured effects on mortality as well, because patients begin VTE therapy earlier. Per ACP‐1, the estimated risk for DVT is lower than for PE, running counter to literature experience[8, 16] and raising issues of face validity. The ACP‐1 review accepts all original definitions of major bleeding, including a 2 g/dL drop in hemoglobin,[12] which commonly occurs without any bleeding or clinical consequence, and bleeding events were ascribed to heparins up to 120 days after randomization, long after they could have been responsible.
Previous meta‐analyses of thromboprophylaxis studies[23, 24] shared many of these same limitations, but did not ascribe bleeding complications to heparins for this extended duration, and had point estimates that suggested a larger impact from prophylaxis than ACP‐1. Dentali et al., for example, showed statistically significant impact on PE (relative risk [RR] 0.43), fatal PE (RR 0.38), and a nearly statistically significant large impact on DVT (RR 0.47, 95% confidence interval [CI]: 0.22‐1.00),[24] whereas ACP‐1 estimated a smaller significant impact on PE (RR 0.69), no significant difference in fatal PE, and a much smaller estimate of the impact on DVT (RR 0.78, 95% CI: 0.45‐1.35) (Table 2).
Baseline Risk | Relative Effect (95% CI) | Absolute Effect per 1000 Patients Treated (95% CI) | |
---|---|---|---|
| |||
ACP guideline review (Lederle), UFH or LMWH vs placebo/no treatment, medical patients | |||
Mortality | 6.6 | OR 0.94 (0.84‐1.04) | 4 fewer (11 fewer to 3 more) |
Major bleeding | 0.25 | OR 1.49 (0.91‐2.43) | 1 more (no effect to 3 more) |
Symptomatic DVT | 0.96 | OR 0.78 (0.45‐1.35) | 2 fewer (6 fewer to 4 more) |
PE | 1.2 | OR 0.69 (0.52‐0.90) | 4 fewer (6 fewer to 1 fewer) |
Fatal PE | 0.30 | OR 0.77 (0.43‐1.37) | 1 fewer (2 fewer to 1 more) |
ACCP AT9 (Kahn), non‐critical care medical inpatients, anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Mortality | 4.5 | OR 0.97 (0.79‐1.19) | 1 fewer (9 fewer to 8 more) |
Major bleeding | 0.40 | OR 1.32 (0.73‐2.37) | 1 more (1 fewer to 6 more) |
Thrombocytopenia | 0.13 | OR 0.92 (0.54‐1.53) | 1 fewer (6 fewer to 7 more) |
Symptomatic DVT | |||
Padua score <4 | 0.2 | RR 0.47 (0.22‐1) | 1 fewer (1 fewer to no effect) |
Padua score 4 | 6.7 | 34 fewer (51 fewer to no effect) | |
ACCP AT9 (Kahn) non‐critical care medical inpatients, Anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Nonfatal PE | |||
Padua score 4 | 0.2 | RR 0.61 (0.23‐1.67) | 1 fewer (1 fewer to 1 more) |
Padua score 4 | 3.9 | 15 fewer (30 fewer to 36 more) | |
Fatal PE | 0.4 | RR 0.41 (0.22‐0.76) | 2 fewer (1 fewer to 3 fewer) |
ACCP AT9 (Kahn), critical care medical inpatients, any heparin (LMWH, UFH) vs placebo/no treatment) | |||
Mortality | 9.4 | RR 1.01 (0.04‐2.57) | 1 more (56 fewer to 148 more) |
Major bleeding | 2.7 | RR 2.09 (0.54‐8.16) | 29 more (12 fewer to 190 more) |
Symptomatic DVT | 5.8 | RR 0.86 (0.59‐1.25) | 4 fewer (12 fewer to 8 more) |
Pulmonary embolus | 4.2 | RR, 0.73 (0.26‐2.11) | 11 fewer (31 fewer to 47 more) |
AT9 used a variety of methods to estimate each component of the risk/benefit equation. Critical care and non‐critical care estimates were generated independently, but because of limited data, the critical care estimates were highly imprecise. In non‐critical care patients, as in ACP‐1, treatment effects were estimated from RCTs that routinely screened for A‐VTE, and they adapted the Dentali et al. estimate of DVT risk reduction. The baseline risk for bleeding and mortality were derived from the control population of the same meta‐analysis.[24]
Using a novel approach, AT9 estimated baseline nonsurgical VTE risk from a prospective observational cohort study of 1180 medical inpatients divided into high‐ and low‐risk groups by a point‐scoring system.[25] Deriving risk estimates from an observational cohort has theoretical advantages. Many patients did not receive prophylaxis, allowing for unadjusted risk estimates; they represented a cross‐section of medical inpatients rather than a selected trial population, and risk estimates were not reduced by the culling of screen‐detected A‐VTE.
The Padua risk‐assessment model (RAM) (Table 3) defines high VTE risk as a cumulative score 4. There were 60.3% of patients at low risk and 39.7% at high risk using this threshold. Among unprophylaxed patients, VTE occurred in 11% of high‐risk patients versus 0.3% of low‐risk patients (hazard ratio 32.0, 95% CI: 4.1251.0).
Baseline Features | Score |
---|---|
| |
Active cancer* | 3 |
Previous VTE (excluding superficial thrombosis) | 3 |
Reduced mobility | 3 |
Already known thrombophilic condition | 3 |
Recent (1 month) trauma and/or surgery | 2 |
Elderly age (70 years) | 1 |
Heart and/or respiratory failure | 1 |
Acute myocardial infarction or stroke | 1 |
Acute infection and/or rheumatologic disorder | 1 |
Obesity (BMI 30) | 1 |
Ongoing hormonal treatment | 1 |
PADUA: A CLOSER LOOK
In the Padua study, 60% of the population appeared to be at such low risk for VTE that prophylaxis would seem unnecessary, but closer scrutiny should raise concern about generalizing these results. Of the 711 low‐risk patients, <1% were immobile, only 6% had cancer, 6% were obese, and only 12% had any acute infection or inflammatory condition, yet their mean length of stay was 7.9 days. These characteristics do not apply to 60% of American inpatients. Furthermore, 964 of 2208 eligible patients (44%) were excluded because they required therapeutic anticoagulation.[25]
Correspondence with the authors revealed that the 2 PEs in patients with Padua scores 4 occurred among 192 patients with a risk score of 3 (Figure 1), a 1% (2/192) risk of PE. This is a very small sample, and the true risk of VTE for medical inpatients with a risk score of 3 may be lower or significantly higher. In the Padua population, a risk score of 3 equated to a VTE risk of 6.9%, whereas those with a score of 0 to 2 had no VTE. For those adapting the Padua model, careful consideration of using a cutoff of 3, versus 4, is warranted.

IMPLICATIONS FOR VTE PROTOCOL IMPLEMENTATION AND IMPROVEMENT TEAMS
AT9 and ACP‐1 sought to focus on S‐VTE, remove bias from recommendations, and highlight potential risks of unnecessary prophylaxis in low‐risk patients. They have largely succeeded in these important goals. However, the complexity of the new guidelines and lack of consensus about VTE risk assessment pose significant challenges to improvement teams tasked with implementing the guidelines in real‐world settings.
CHOOSING A VTE RAM
The fundamental question is: How can hospitals assess VTE risk, assure adequate prophylaxis for patients who need it, while minimizing excess prophylaxis, in a practical, efficient way?
Approach 1: Opt Out Approach
Both guidelines discourage universal prophylaxis for inpatients without contraindications unless the physician opts out. Although the simplicity of this approach is appealing, the low rate of VTE in a substantial segment of the medical inpatient population and known risks of thromboprophylaxis make this strategy suboptimal.
Approach 2: No VTE RAM
ACP‐1 notes that evidence is not sufficient to recommend 1 RAM over another, and essentially advises leaving prophylaxis decisions up to an individual physician's judgment. Although the evidence may not prove which system is best, prophylaxis reliability is dismal when there is no system or when hospitals offer prophylaxis options without guidance.[26, 27] Widespread, well‐documented underprophylaxis[16, 17, 18, 19] is largely the result of relying on unguided physician judgment and relatively passive interventions like educational sessions and pocket cards.[8] This approach also deprives improvement teams of standard definitions of VTE risk, bleeding risk, and adequate prophylaxis necessary to measure and improve VTE prophylaxis. Because of significant gray areas in the literature and varied infrastructure, institutions will not implement identical VTE prevention programs, but institutional standardization remains a cornerstone of improvement.
Approach 3: Buckets of Risk
The AT8 approach to risk assessment was to place patients into VTE risk groups described in the text, rather than have an individualized point‐scoring system.[11] These assessments can be made in seconds with high levels of interobserver agreement, implemented without undue effort, and spur high levels of compliance.[28, 29] Most importantly, implementation was associated with a 40% reduction in hospital‐associated VTE (RR 0.69, 95% CI: 0.470.79) without detectable increases in bleeding or heparin‐induced thrombocytopenia. Although this strategy has not been tested in randomized trials, it has been replicated in multiple real‐world settings that avoid concerns about generalizability due to imperfect trial populations.[28, 30]
The most popular bucket model in common use, derived from a table in the AT8 guidelines, is similar to models presented in UK National Institute for Health and Care Excellence guidelines for medical inpatients.[31] These models are potentially less precise than point‐based systems, but offer simplicity, ease of use, and improved physician acceptance, and thus may be more effective than point‐based models in settings without advanced clinical decision support. The models are flexible to reflect greater or lesser degrees of aggressiveness in defining risk categories, and can be used to approximate some point‐based systems.
Approach 4: Individualized Point‐Based RAM
AT9 authors used the Padua VTE RAM to define low‐ and high‐risk patients for VTE in their recommendation for medical inpatients. The Padua model appears relatively simple, but it does require calculations, and there is a paucity of data for implementation experience with it. As mentioned above, if teams use the Padua model, the optimal cutoff (3 vs 4) for recommending prophylaxis is uncertain, and both should be considered.
The Caprini point‐based system is not mentioned in the guideline for thromboprophylaxis in medical inpatients, but in our collaborative improvement experience, it is perhaps the most commonly used point‐based model for medical inpatients.[28, 30] It is also embedded in AT9 recommendations for prophylaxis in the nonorthopedic surgical population,[9] and thus is tempting to use for both medical and surgical patients. There are several caveats to those considering the use of these more complex point‐based models. Complex point‐based RAM suffer from poor interobserver agreement.[32] They have also had limited ability to exclude low‐risk patients from prophylaxis in validation studies,[33] and have not been tested extensively in medical populations. Although AT9 considers the Caprini RAM relatively easy to use,[9] our experience in collaboratives suggests that for many hospitals, the model is too complex to be used reliably.[28, 30] Clinicians often simply bypass the clinical decision support offered in the tool, rather than checking off all risk factors, adding up the point total, and identifying the appropriate prophylaxis choices based on the point total.[28] Other point‐based RAM (reviewed elsewhere[34, 35, 36]) pose similar implementation challenges.
On the other hand, centers with more sophisticated clinical decision support and a strong improvement framework can overcome some of these challenges to get good results with complex point‐based models. A forcing function can ensure that practitioners complete all risk‐assessment tasks. Providers can check off the VTE risk factors and bleeding risk factors on 1 screen, and several factors like age, body mass index, and renal function can be autopopulated. Instead of asking the provider to add up points, the combination of answers checked off on the first screen can drive behind‐the‐scenes calculations and seamlessly lead providers to prophylaxis choices appropriate for that combination of VTE and bleeding risks. Customized models can be designed for a wide variety of services. Similar strategies can ease adaption with more complex qualitative models as well.[37]
BOTTOM LINE IN CHOOSING A VTE RAM
Many medical inpatients are at high risk for VTE, but others are not at sufficient risk to warrant prophylaxis. VTE risk assessment should be embedded in admission, transfer, and perioperative order sets and may need a hard stop to insure completion. There is a trend to favor individualized point‐based models over models that place patients in groups of risk, but evidence is insufficient to recommend 1 type of RAM over another, and more complex point‐based models often require extensive local customization and algorithmic clinical decision support to effectively implement them. Centers without advanced capability may find the bucket models more effective. We urge improvement teams to trial their RAM with common patient case scenarios, and to make a choice based on an effort‐benefit analysis, feedback from their clinicians, and the level of customization in clinical decision support available to them.
OTHER IMPLEMENTATION STRATEGIES
VTE and bleeding risk change during hospitalization. We have used ongoing daily surveillance and measurement of patients on no prophylaxis to prompt concurrent intervention (ie, measure‐vention) to increase prophylaxis for patients at risk.[28] Improvement teams should focus not only on increasing prophylaxis for those at risk, but should also use measure‐vention, checklists, or other techniques to identify low‐risk (eg, ambulating) patients for cessation of overly aggressive prophylaxis. Efforts to improve early progressive ambulation, limit central venous catheters to those who truly need them, and improve adherence to mechanical prophylaxis can also reduce VTE, as well as benefitting patient populations in other ways.
We recognize there are several approaches to close the implementation gap in delivering thromboprophylaxis judiciously but reliably, and encourage research and publication of varied strategies. Last, we hope efforts to limit unnecessary prophylaxis and challenges inherent in implementing new and complex guidelines do not increase the morbidity and mortality of hospital‐acquired VTE, by derailing the delivery of prophylaxis to those in whom the benefits outweigh the risks.
Disclosures: Dr. Merli has conducted research for Johnson & Johnson, Bristol Myers Squibb, and Portala Scientific and has been a consultant for Johnson & Johnson and Bristol Myers Squibb.
Patients hospitalized for acute medical illness have more than a 10‐fold increased risk for venous thromboembolism (VTE),[1] with an undeniably dramatic, negative impact on the lives of those afflicted, including fatal pulmonary embolism (PE), which most commonly affects patients on the medical service.[2, 3, 4] Yet estimates for the overall rate of VTE in this population are relatively low, raising questions about which subsets of medical patients warrant the risk and cost of prophylaxis.
Recently, the American College of Physicians published guidelines (ACP‐1)[5] and a supporting review[6] addressing VTE prophylaxis in nonsurgical inpatients, followed by publication of the American College of Chest Physicians (ACCP) 9th Edition of the Chest Guidelines on Antithrombotic Therapy and Prevention of Thrombosis (AT9),[7] which divides VTE prevention into 3 articles,[8, 9, 10] including 1 on nonsurgical patients.[8] Both ACP‐1 and AT9 differ significantly from the 2008 ACCP guidelines (AT8),[11] but took different approaches to methodology, risk assessment, and several other aspects of thromboprophylaxis (Table 1). This narrative review summarizes and compares these recommendations and the methods used to arrive at them, with a final section focusing on implications for improvement teams designing order sets and system changes to address VTE prophylaxis.
2008 ACCP VTE Guideline AT8 | 2012 ACCP VTE Guideline AT9 | 2011 ACP Guideline | |
---|---|---|---|
| |||
Stance on asymptomatic VTE end points | Because of the strong concordance between asymptomatic DVT and clinically important VTE, we believe that DVT detected by a sensitive screening tesis an appropriate outcome in the early assessment of new thromboprophylaxis interventions. | Use of this surrogate (asymptomatic, screening‐detected thrombosis) creates major problems in making the trade‐off between patient‐important outcomes (thrombosis and serious bleeding). | Surrogate outcomes of asymptomatic screening detected‐thrombosis should not be used. |
Who should be prophylaxed? | 6.0.0: For acutely ill medical patients admitted to hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, including active cancer, previous VTE, sepsis, neurologic disease, or inflammatory bowel disease, we recommend thromboprophylaxis with LMWH (1A), UFH (1A), or fondaparinux (1A). | 2.3: For acutely ill hospitalized medical patients at increased risk for thrombosis, we recommend anticoagulant thromboprophylaxis, with LMWH, UFH bid, UFH tid, or fondaparinux (1B). | ACP recommends pharmacologic prophylaxis with heparin or a related drug for venous thromboembolism in medical (including stroke) patients unless the assessed risk for bleeding outweighs the likely benefits (grade: strong recommendation, moderate‐quality evidence). |
2.4: For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic or mechanical prophylaxis. (1B) | |||
Choice of anticoagulant prophylaxis | There is no compelling evidence that UFH should be administered three times daily in preference to twice daily in medical patients, although these two regimens have never been directly compared. | In choosing the specific anticoagulant drug to be used for pharmacoprophylaxis, choices should be based on patient preference, compliance, and ease of administration (eg, daily vs bid vs tid dosing), as well as on local factors affecting acquisition costs. | [T]he choice of agent for prophylaxis of VTE should be based on ease of use, adverse effect profile, and cost of medication. |
No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | No strong preference LMWH vs UFH. | |
Mechanical prophylaxis | 1.4.3.1: We recommend that mechanical methods of prophylaxis be used primarily in patients at high risk of bleeding (grade 1A), or possibly as an adjunct to anticoagulant‐based thromboprophylaxis (grade 2A). | 2.7.2: For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or at high risk for major bleeding, we suggest the optimal use of mechanical thromboprophylaxis with GCS (grade 2C) or IPC (grade 2C). | ACP recommends against the use of mechanical prophylaxis with graduated compression stockings for prevention of venous thromboembolism (grade: strong recommendation, moderate‐quality evidence). |
No strong evidence for IPC vs GCS | |||
Duration | [T]he optimal duration of thromboprophylaxis remains unclear. To the end of hospitalization for most patients. | 2.8: [W]e suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (2B). | The optimal duration of heparin prophylaxis is uncertain. |
Risk Stratification | The approach of individual prophylaxis prescribing based on formal RAMs is not used routinely by most clinicians because it has not been adequately validated and is cumbersome. Individual RAMs may not be worth the effort, because there are only a limited number of thromboprophylaxis options, and one of the principles of effective thromboprophylaxis is to reduce complexity in decision making. | (Noncritical care) No formal risk assessment recommendation. Padua point‐based model is inherent in definitions of baseline VTE risk. | ACP does not support the application of performance measures in medical (including stroke) patients that promotes universal venous thromboembolism prophylaxis regardless of risk. |
Another approach involves implementation of group‐specific thromboprophylaxis routinely for all patients who belong to each of the major target groups. We support this approach. | There are no validated risk assessment models to stratify VTE risk in critically ill patients. | Many risk assessment tools are available for estimating thromboembolism risk, but the current evidence is insufficient to recommend a validated tool. | |
[T]he decision is best left to physician judgment, and performance measures targeting all patients are inappropriate. |
WHY ARE THE NEW GUIDELINES DIFFERENT?
Major randomized controlled trials (RCTs)[12, 13, 14] of thromboprophylaxis used routine deep vein thrombosis (DVT) surveillance and included both symptomatic (S‐VTE) and asymptomatic VTE (A‐VTE) end points. These studies consistently demonstrated 44% to 63% reductions in VTE without increases in major bleeding.[11] Because of the strong relationship between A‐VTE and S‐VTE outcomes, and a paucity of studies using only S‐VTE outcomes, AT8 judged that A‐VTE outcomes were valid to include, whereas the new guidelines reject the use of asymptomatic VTE end points.[5, 8, 15] To minimize financial and intellectual conflicts of interest, AT9 also used methodologists rather than VTE experts as topic editors, excluded conflicted experts from voting on recommendations, and attempted to estimate patient values and preferences.[15] As a result, AT9 makes fewer strong recommendations (182 1A recommendations in 2008, but only 29 in 2012), replacing them with weak suggestions.
WHAT DO THE NEW GUIDELINES RECOMMEND?
AT8 recommended anticoagulant prophylaxis for acutely ill medical inpatients with known risk factors, but did not recommend routine thromboprophylaxis. However, because of well‐known problems with underprophylaxis,[16, 17, 18, 19] particularly in medical patients, the low risk of bleeding, and difficulties with explicitly defining low‐risk patients, many discounted the need for VTE risk stratification.
Both new guidelines recommend prophylaxis for many nonsurgical patients, but discourage routine thromboprophylaxis for nonsurgical inpatients. AT9 specifically recommends against any thromboprophylaxis for low‐risk medical inpatients, implying that many nonsurgical, non‐critical care patients belong in this category, citing lower estimates of benefit, lower estimates of VTE risk, and potential bleeding risks.
The guidelines[5, 8] agree that, when indicated and absent contraindications, anticoagulant prophylaxis is preferred over mechanical prophylaxis, and agree there is insufficient evidence to recommend 1 anticoagulant over another.
For patients at risk of both VTE and bleeding, ACP‐1 states that intermittent pneumatic compression (IPC) devices are a reasonable option, given the evidence showing benefit in surgical patients. However, ACP‐1 recommends against graduated compression stockings (GCS) in nonsurgical patients based on a meta‐analysis dominated by the CLOTS‐1 (Clots in Legs Or sTockings after Stroke) trial, which found that thigh‐high GCS increased the risk of skin breakdown without reducing VTE[20] in immobilized stroke patients. AT9 does not recommend against GCS for patients facing bleeding and VTE risk. AT9 notes the hazards of generalizing results from stroke patients, and also considers the somewhat contradictory results from the CLOTS‐2 trial in stroke patients, which found a lower rate of VTE with thigh‐high GCS than with knee‐high GCS.[21] AT9 designates a recommendation of 2C for either IPC devices or thigh‐high GCS for those at VTE risk when anticoagulants are contraindicated.
Combination mechanical‐pharmacologic prophylaxis has proven superior in some surgical populations, and many hospitals use combined prophylaxis in high‐risk medical patients. However, combination prophylaxis has not been studied in this population. ACP‐1 does not comment on the practice; AT9 does not recommend for or against it. Institutions that use combination prophylaxis should be aware that although it may seem logical to extrapolate estimates of benefit seen in selected surgical patients, this is not a recommended practice.
RCTs for thromboprophylaxis in nonsurgical inpatients provided prophylaxis for 6 to 21 days. Neither ACP‐1 or AT9 recommend routinely extending prophylaxis beyond the hospital stay, citing an RCT[22] in which the benefit of extended duration low molecular weight heparin was limited to selected subsets of patients and offset by bleeding complications. AT9 suggests prophylaxis for 6 to 21 days, until full mobility is restored, or until dischargewhichever comes first.[8] However, we know of no study that establishes a mobility level at which prophylaxis can be safely discontinued, especially in inpatients with multiple risk factors.
ESTIMATING RISK AND BENEFIT OF PROPHYLAXIS AND LIMITATIONS OF METHODS
Calculating risk/benefit ratios for thromboprophylaxis requires estimates of baseline VTE and bleeding risks, and estimates of the impact of prophylaxis on those baseline risks. Methods to estimate the impact of prophylaxis on S‐VTE from studies relying on A‐VTE all have limitations, as acknowledged by the AT9 introduction.[15]
The ACP‐1 review found the only significant effect of prophylaxis on medical inpatients was a modest reduction in PE and a modest increase in total bleeding events, without effects on major bleeding, DVT, or mortality.[6] The authors summarized the findings as indicative of little or no net benefit for the medical population as a whole. The ACP‐1 review derives estimates of S‐VTE risk, bleeding, and mortality from control (baseline) and interventional arms of RCTs that used routine VTE screening, and included A‐VTE end points. The baseline risk of VTE could potentially be overestimated, because the populations in the trials are not representative of the entire medical population.
On the other hand, pooling trials with screening‐detected VTE to estimate S‐VTE outcomes is a questionable practice that may falsely lower estimates of VTE prophylaxis benefit. Screening‐detected VTE may be treated or declared a study end point before it becomes symptomatic. MEDENOX (Medical Patients With Enoxaparin) is an illustrative example.[12] The 263 placebo recipients suffered 37 A‐VTEs and 4 S‐VTEs. The 272 enoxaparin recipients suffered 17 A‐VTEs and 3 S‐VTEs. Patients at the highest risk of S‐VTE were counted as reaching an end point before they could develop symptoms; this happened more than twice as often in the placebo arm. This decreases both estimates of baseline VTE risk and the measured benefit of prophylaxis for S‐VTE. Screening could conceivably reduce measured effects on mortality as well, because patients begin VTE therapy earlier. Per ACP‐1, the estimated risk for DVT is lower than for PE, running counter to literature experience[8, 16] and raising issues of face validity. The ACP‐1 review accepts all original definitions of major bleeding, including a 2 g/dL drop in hemoglobin,[12] which commonly occurs without any bleeding or clinical consequence, and bleeding events were ascribed to heparins up to 120 days after randomization, long after they could have been responsible.
Previous meta‐analyses of thromboprophylaxis studies[23, 24] shared many of these same limitations, but did not ascribe bleeding complications to heparins for this extended duration, and had point estimates that suggested a larger impact from prophylaxis than ACP‐1. Dentali et al., for example, showed statistically significant impact on PE (relative risk [RR] 0.43), fatal PE (RR 0.38), and a nearly statistically significant large impact on DVT (RR 0.47, 95% confidence interval [CI]: 0.22‐1.00),[24] whereas ACP‐1 estimated a smaller significant impact on PE (RR 0.69), no significant difference in fatal PE, and a much smaller estimate of the impact on DVT (RR 0.78, 95% CI: 0.45‐1.35) (Table 2).
Baseline Risk | Relative Effect (95% CI) | Absolute Effect per 1000 Patients Treated (95% CI) | |
---|---|---|---|
| |||
ACP guideline review (Lederle), UFH or LMWH vs placebo/no treatment, medical patients | |||
Mortality | 6.6 | OR 0.94 (0.84‐1.04) | 4 fewer (11 fewer to 3 more) |
Major bleeding | 0.25 | OR 1.49 (0.91‐2.43) | 1 more (no effect to 3 more) |
Symptomatic DVT | 0.96 | OR 0.78 (0.45‐1.35) | 2 fewer (6 fewer to 4 more) |
PE | 1.2 | OR 0.69 (0.52‐0.90) | 4 fewer (6 fewer to 1 fewer) |
Fatal PE | 0.30 | OR 0.77 (0.43‐1.37) | 1 fewer (2 fewer to 1 more) |
ACCP AT9 (Kahn), non‐critical care medical inpatients, anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Mortality | 4.5 | OR 0.97 (0.79‐1.19) | 1 fewer (9 fewer to 8 more) |
Major bleeding | 0.40 | OR 1.32 (0.73‐2.37) | 1 more (1 fewer to 6 more) |
Thrombocytopenia | 0.13 | OR 0.92 (0.54‐1.53) | 1 fewer (6 fewer to 7 more) |
Symptomatic DVT | |||
Padua score <4 | 0.2 | RR 0.47 (0.22‐1) | 1 fewer (1 fewer to no effect) |
Padua score 4 | 6.7 | 34 fewer (51 fewer to no effect) | |
ACCP AT9 (Kahn) non‐critical care medical inpatients, Anticoagulant (LMWH, UFH, fondaparinux) vs placebo/no treatment) | |||
Nonfatal PE | |||
Padua score 4 | 0.2 | RR 0.61 (0.23‐1.67) | 1 fewer (1 fewer to 1 more) |
Padua score 4 | 3.9 | 15 fewer (30 fewer to 36 more) | |
Fatal PE | 0.4 | RR 0.41 (0.22‐0.76) | 2 fewer (1 fewer to 3 fewer) |
ACCP AT9 (Kahn), critical care medical inpatients, any heparin (LMWH, UFH) vs placebo/no treatment) | |||
Mortality | 9.4 | RR 1.01 (0.04‐2.57) | 1 more (56 fewer to 148 more) |
Major bleeding | 2.7 | RR 2.09 (0.54‐8.16) | 29 more (12 fewer to 190 more) |
Symptomatic DVT | 5.8 | RR 0.86 (0.59‐1.25) | 4 fewer (12 fewer to 8 more) |
Pulmonary embolus | 4.2 | RR, 0.73 (0.26‐2.11) | 11 fewer (31 fewer to 47 more) |
AT9 used a variety of methods to estimate each component of the risk/benefit equation. Critical care and non‐critical care estimates were generated independently, but because of limited data, the critical care estimates were highly imprecise. In non‐critical care patients, as in ACP‐1, treatment effects were estimated from RCTs that routinely screened for A‐VTE, and they adapted the Dentali et al. estimate of DVT risk reduction. The baseline risk for bleeding and mortality were derived from the control population of the same meta‐analysis.[24]
Using a novel approach, AT9 estimated baseline nonsurgical VTE risk from a prospective observational cohort study of 1180 medical inpatients divided into high‐ and low‐risk groups by a point‐scoring system.[25] Deriving risk estimates from an observational cohort has theoretical advantages. Many patients did not receive prophylaxis, allowing for unadjusted risk estimates; they represented a cross‐section of medical inpatients rather than a selected trial population, and risk estimates were not reduced by the culling of screen‐detected A‐VTE.
The Padua risk‐assessment model (RAM) (Table 3) defines high VTE risk as a cumulative score 4. There were 60.3% of patients at low risk and 39.7% at high risk using this threshold. Among unprophylaxed patients, VTE occurred in 11% of high‐risk patients versus 0.3% of low‐risk patients (hazard ratio 32.0, 95% CI: 4.1251.0).
Baseline Features | Score |
---|---|
| |
Active cancer* | 3 |
Previous VTE (excluding superficial thrombosis) | 3 |
Reduced mobility | 3 |
Already known thrombophilic condition | 3 |
Recent (1 month) trauma and/or surgery | 2 |
Elderly age (70 years) | 1 |
Heart and/or respiratory failure | 1 |
Acute myocardial infarction or stroke | 1 |
Acute infection and/or rheumatologic disorder | 1 |
Obesity (BMI 30) | 1 |
Ongoing hormonal treatment | 1 |
PADUA: A CLOSER LOOK
In the Padua study, 60% of the population appeared to be at such low risk for VTE that prophylaxis would seem unnecessary, but closer scrutiny should raise concern about generalizing these results. Of the 711 low‐risk patients, <1% were immobile, only 6% had cancer, 6% were obese, and only 12% had any acute infection or inflammatory condition, yet their mean length of stay was 7.9 days. These characteristics do not apply to 60% of American inpatients. Furthermore, 964 of 2208 eligible patients (44%) were excluded because they required therapeutic anticoagulation.[25]
Correspondence with the authors revealed that the 2 PEs in patients with Padua scores 4 occurred among 192 patients with a risk score of 3 (Figure 1), a 1% (2/192) risk of PE. This is a very small sample, and the true risk of VTE for medical inpatients with a risk score of 3 may be lower or significantly higher. In the Padua population, a risk score of 3 equated to a VTE risk of 6.9%, whereas those with a score of 0 to 2 had no VTE. For those adapting the Padua model, careful consideration of using a cutoff of 3, versus 4, is warranted.

IMPLICATIONS FOR VTE PROTOCOL IMPLEMENTATION AND IMPROVEMENT TEAMS
AT9 and ACP‐1 sought to focus on S‐VTE, remove bias from recommendations, and highlight potential risks of unnecessary prophylaxis in low‐risk patients. They have largely succeeded in these important goals. However, the complexity of the new guidelines and lack of consensus about VTE risk assessment pose significant challenges to improvement teams tasked with implementing the guidelines in real‐world settings.
CHOOSING A VTE RAM
The fundamental question is: How can hospitals assess VTE risk, assure adequate prophylaxis for patients who need it, while minimizing excess prophylaxis, in a practical, efficient way?
Approach 1: Opt Out Approach
Both guidelines discourage universal prophylaxis for inpatients without contraindications unless the physician opts out. Although the simplicity of this approach is appealing, the low rate of VTE in a substantial segment of the medical inpatient population and known risks of thromboprophylaxis make this strategy suboptimal.
Approach 2: No VTE RAM
ACP‐1 notes that evidence is not sufficient to recommend 1 RAM over another, and essentially advises leaving prophylaxis decisions up to an individual physician's judgment. Although the evidence may not prove which system is best, prophylaxis reliability is dismal when there is no system or when hospitals offer prophylaxis options without guidance.[26, 27] Widespread, well‐documented underprophylaxis[16, 17, 18, 19] is largely the result of relying on unguided physician judgment and relatively passive interventions like educational sessions and pocket cards.[8] This approach also deprives improvement teams of standard definitions of VTE risk, bleeding risk, and adequate prophylaxis necessary to measure and improve VTE prophylaxis. Because of significant gray areas in the literature and varied infrastructure, institutions will not implement identical VTE prevention programs, but institutional standardization remains a cornerstone of improvement.
Approach 3: Buckets of Risk
The AT8 approach to risk assessment was to place patients into VTE risk groups described in the text, rather than have an individualized point‐scoring system.[11] These assessments can be made in seconds with high levels of interobserver agreement, implemented without undue effort, and spur high levels of compliance.[28, 29] Most importantly, implementation was associated with a 40% reduction in hospital‐associated VTE (RR 0.69, 95% CI: 0.470.79) without detectable increases in bleeding or heparin‐induced thrombocytopenia. Although this strategy has not been tested in randomized trials, it has been replicated in multiple real‐world settings that avoid concerns about generalizability due to imperfect trial populations.[28, 30]
The most popular bucket model in common use, derived from a table in the AT8 guidelines, is similar to models presented in UK National Institute for Health and Care Excellence guidelines for medical inpatients.[31] These models are potentially less precise than point‐based systems, but offer simplicity, ease of use, and improved physician acceptance, and thus may be more effective than point‐based models in settings without advanced clinical decision support. The models are flexible to reflect greater or lesser degrees of aggressiveness in defining risk categories, and can be used to approximate some point‐based systems.
Approach 4: Individualized Point‐Based RAM
AT9 authors used the Padua VTE RAM to define low‐ and high‐risk patients for VTE in their recommendation for medical inpatients. The Padua model appears relatively simple, but it does require calculations, and there is a paucity of data for implementation experience with it. As mentioned above, if teams use the Padua model, the optimal cutoff (3 vs 4) for recommending prophylaxis is uncertain, and both should be considered.
The Caprini point‐based system is not mentioned in the guideline for thromboprophylaxis in medical inpatients, but in our collaborative improvement experience, it is perhaps the most commonly used point‐based model for medical inpatients.[28, 30] It is also embedded in AT9 recommendations for prophylaxis in the nonorthopedic surgical population,[9] and thus is tempting to use for both medical and surgical patients. There are several caveats to those considering the use of these more complex point‐based models. Complex point‐based RAM suffer from poor interobserver agreement.[32] They have also had limited ability to exclude low‐risk patients from prophylaxis in validation studies,[33] and have not been tested extensively in medical populations. Although AT9 considers the Caprini RAM relatively easy to use,[9] our experience in collaboratives suggests that for many hospitals, the model is too complex to be used reliably.[28, 30] Clinicians often simply bypass the clinical decision support offered in the tool, rather than checking off all risk factors, adding up the point total, and identifying the appropriate prophylaxis choices based on the point total.[28] Other point‐based RAM (reviewed elsewhere[34, 35, 36]) pose similar implementation challenges.
On the other hand, centers with more sophisticated clinical decision support and a strong improvement framework can overcome some of these challenges to get good results with complex point‐based models. A forcing function can ensure that practitioners complete all risk‐assessment tasks. Providers can check off the VTE risk factors and bleeding risk factors on 1 screen, and several factors like age, body mass index, and renal function can be autopopulated. Instead of asking the provider to add up points, the combination of answers checked off on the first screen can drive behind‐the‐scenes calculations and seamlessly lead providers to prophylaxis choices appropriate for that combination of VTE and bleeding risks. Customized models can be designed for a wide variety of services. Similar strategies can ease adaption with more complex qualitative models as well.[37]
BOTTOM LINE IN CHOOSING A VTE RAM
Many medical inpatients are at high risk for VTE, but others are not at sufficient risk to warrant prophylaxis. VTE risk assessment should be embedded in admission, transfer, and perioperative order sets and may need a hard stop to insure completion. There is a trend to favor individualized point‐based models over models that place patients in groups of risk, but evidence is insufficient to recommend 1 type of RAM over another, and more complex point‐based models often require extensive local customization and algorithmic clinical decision support to effectively implement them. Centers without advanced capability may find the bucket models more effective. We urge improvement teams to trial their RAM with common patient case scenarios, and to make a choice based on an effort‐benefit analysis, feedback from their clinicians, and the level of customization in clinical decision support available to them.
OTHER IMPLEMENTATION STRATEGIES
VTE and bleeding risk change during hospitalization. We have used ongoing daily surveillance and measurement of patients on no prophylaxis to prompt concurrent intervention (ie, measure‐vention) to increase prophylaxis for patients at risk.[28] Improvement teams should focus not only on increasing prophylaxis for those at risk, but should also use measure‐vention, checklists, or other techniques to identify low‐risk (eg, ambulating) patients for cessation of overly aggressive prophylaxis. Efforts to improve early progressive ambulation, limit central venous catheters to those who truly need them, and improve adherence to mechanical prophylaxis can also reduce VTE, as well as benefitting patient populations in other ways.
We recognize there are several approaches to close the implementation gap in delivering thromboprophylaxis judiciously but reliably, and encourage research and publication of varied strategies. Last, we hope efforts to limit unnecessary prophylaxis and challenges inherent in implementing new and complex guidelines do not increase the morbidity and mortality of hospital‐acquired VTE, by derailing the delivery of prophylaxis to those in whom the benefits outweigh the risks.
Disclosures: Dr. Merli has conducted research for Johnson & Johnson, Bristol Myers Squibb, and Portala Scientific and has been a consultant for Johnson & Johnson and Bristol Myers Squibb.
- US Department of Health and Human Services. Surgeon General's call to action to prevent deep vein thrombosis and pulmonary embolism. 2008. Available at: http://www.surgeongeneral.gov/topics/deepvein/index.html. Accessed January 29, 2013.
- Incidence of venous thromboembolism in hospitalized patients vs. community residents. Mayo Clin Proc. 2001;76:1102–1110. , , , et al.
- Risk factors for deep vein thrombosis and pulmonary embolism: a population‐based case‐control study. Arch Intern Med. 2000;160(6):809–815. , , , , , .
- New onset of venous thromboembolism among hospitalized patients at Brigham and Women's Hospital is caused more often by prophylaxis failure than by withholding treatment. Chest. 2000;118(6):1680–1684. , , .
- venous thromboembolism prophylaxis in hospitalized patients: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2011;155(9):625–632. , , , , .
- Venous thromboembolism prophylaxis in hospitalized medical patients and those with stroke: a background review for an American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2011;155(9):602–615. , , , .
- Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):e419S–e494S. , , , et al.
- Prevention of VTE in nonsurgical patients. Chest. 2012;141(2 suppl):e195S–e226S. , , , et al.
- Prevention of VTE in nonorthopedic surgical patients. Chest. 2012;141(2 suppl):e227S–e277S. , , , et al.
- Prevention of VTE in orthopedic surgery patients. Chest. 2012;141(2 suppl):e278S–e325S. , , , et al.
- Prevention of venous thromboembolism. Chest. 2008;133(6 suppl):381S–453S. , , , et al.
- A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. Prophylaxis in Medical Patients with Enoxaparin Study Group. N Engl J Med. 1999;341(11):793–800. , , , et al.
- Randomized, placebo‐controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. Circulation. 2004;110(7):874–879. , , , et al.
- Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial. BMJ. 2006;332(7537):325–329. , , , et al.
- Introduction to the ninth edition: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):48S–52S. , , , , , .
- The outcome after treatment of venous thromboembolism is different in surgical and acutely ill medical patients. Findings from the RIETE registry. J Thromb Haemost. 2004;2:1892–1898. , , , et al.
- Venous thromboembolism prophylaxis in acutely ill hospitalized medical patients: findings from the International Medical Prevention Registry on Venous Thromboembolism. Chest. 2007;132(3):936–945. , , , et al.
- Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross‐sectional study. Lancet. 2008;371(9610):387–394. , , , et al.
- ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in hospitalised medically ill patients. The ENDORSE Global Survey. Thromb Haemost. 2010;103(4):736–748. , , , et al.;
- CLOTS Trials Collaboration. Effectiveness of thigh‐length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomized controlled trial. Lancet. 2009;373(9679):1958–1965. , , , et al;
- CLOTS (Clots in Legs Or sTockings after Stroke) Trial Collaboration. Thigh‐length versus below‐knee stockings for deep venous thrombosis prophylaxis after stroke: a randomized trial. Ann Intern Med. 2010;153(9):553–562.
- Extended‐duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility: a randomized trial. Ann Intern Med. 2010;153:8–18. , , , et al.
- Pharmacological venous thromboembolism prophylaxis in hospitalized medical patients: a meta‐analysis of randomized controlled trials. Arch Intern Med. 2007;167(1)476–486. , , , , .
- Meta‐analysis: anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients. Ann Intern Med. 2007; 46(4):278–288. , , , , .
- A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score. J Thromb Haemost. 2010;8(11):2450–2457. , , , et al.
- Medical admission order sets to improve deep vein thrombosis prophylaxis rates and other outcomes. J Hosp Med. 2009;4(2):81–89. , , , .
- Medical admission order sets to improve deep vein thrombosis prevention: a model for others or a prescription for mediocrity? J Hosp Med. 2009;4(2):77–80. .
- Designing and implementing effective VTE prevention protocols: lessons from collaboratives. J Thromb Thrombolysis. 2010;29(2):159–166. , .
- Optimizing prevention of hospital acquired venous thromboembolism: prospective validation of a VTE risk assessment model. J Hosp Med. 2010;5(1):10–18. , , , et al.
- 2011 John M. Eisenberg Patient Safety and Quality Awards. Mentored implementation: building leaders and achieving results through a collaborative improvement model. Innovation in patient safety and quality at the national level. Jt Comm J Qual Patient Saf. 2012;38(7):301–310. , , , et al.
- NHS National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. NICE Clinical Guideline 92. 2010. Available at: http://www.nice.org.uk/guidance/CG92. Accessed April 18, 2013.
- Reliability of a point‐based VTE risk assessment tool in the hands of medical residents. J Hosp Med. 2011;6:195–201. , , , , .
- A validation of a retrospective venous thromboembolism risk scoring method. Ann Surg. 2010;251(2):344–350. , , , , , .
- Risk assessment models for thromboprophylaxis of medical patients. Thromb Res. 2012;129:127–132. , , , .
- Risk‐assessment models for predicting venous thromboembolism among hospitalized non‐surgical patients: a systematic review. J Thromb Thrombolysis. 2013;35:67–80. , , , , .
- The use of weighted and scored risk assessment models for venous thromboembolism. Thromb Haemost. 2012;108(6):1072–1076. , , .
- Lessons from the Johns Hopkins Multi‐Disciplinary Venous Thromboembolism (VTE) Prevention Collaborative. BMJ. 2012;344:e3935. , , , et al.
- US Department of Health and Human Services. Surgeon General's call to action to prevent deep vein thrombosis and pulmonary embolism. 2008. Available at: http://www.surgeongeneral.gov/topics/deepvein/index.html. Accessed January 29, 2013.
- Incidence of venous thromboembolism in hospitalized patients vs. community residents. Mayo Clin Proc. 2001;76:1102–1110. , , , et al.
- Risk factors for deep vein thrombosis and pulmonary embolism: a population‐based case‐control study. Arch Intern Med. 2000;160(6):809–815. , , , , , .
- New onset of venous thromboembolism among hospitalized patients at Brigham and Women's Hospital is caused more often by prophylaxis failure than by withholding treatment. Chest. 2000;118(6):1680–1684. , , .
- venous thromboembolism prophylaxis in hospitalized patients: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2011;155(9):625–632. , , , , .
- Venous thromboembolism prophylaxis in hospitalized medical patients and those with stroke: a background review for an American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2011;155(9):602–615. , , , .
- Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):e419S–e494S. , , , et al.
- Prevention of VTE in nonsurgical patients. Chest. 2012;141(2 suppl):e195S–e226S. , , , et al.
- Prevention of VTE in nonorthopedic surgical patients. Chest. 2012;141(2 suppl):e227S–e277S. , , , et al.
- Prevention of VTE in orthopedic surgery patients. Chest. 2012;141(2 suppl):e278S–e325S. , , , et al.
- Prevention of venous thromboembolism. Chest. 2008;133(6 suppl):381S–453S. , , , et al.
- A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. Prophylaxis in Medical Patients with Enoxaparin Study Group. N Engl J Med. 1999;341(11):793–800. , , , et al.
- Randomized, placebo‐controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. Circulation. 2004;110(7):874–879. , , , et al.
- Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial. BMJ. 2006;332(7537):325–329. , , , et al.
- Introduction to the ninth edition: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence‐Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):48S–52S. , , , , , .
- The outcome after treatment of venous thromboembolism is different in surgical and acutely ill medical patients. Findings from the RIETE registry. J Thromb Haemost. 2004;2:1892–1898. , , , et al.
- Venous thromboembolism prophylaxis in acutely ill hospitalized medical patients: findings from the International Medical Prevention Registry on Venous Thromboembolism. Chest. 2007;132(3):936–945. , , , et al.
- Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross‐sectional study. Lancet. 2008;371(9610):387–394. , , , et al.
- ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in hospitalised medically ill patients. The ENDORSE Global Survey. Thromb Haemost. 2010;103(4):736–748. , , , et al.;
- CLOTS Trials Collaboration. Effectiveness of thigh‐length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomized controlled trial. Lancet. 2009;373(9679):1958–1965. , , , et al;
- CLOTS (Clots in Legs Or sTockings after Stroke) Trial Collaboration. Thigh‐length versus below‐knee stockings for deep venous thrombosis prophylaxis after stroke: a randomized trial. Ann Intern Med. 2010;153(9):553–562.
- Extended‐duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility: a randomized trial. Ann Intern Med. 2010;153:8–18. , , , et al.
- Pharmacological venous thromboembolism prophylaxis in hospitalized medical patients: a meta‐analysis of randomized controlled trials. Arch Intern Med. 2007;167(1)476–486. , , , , .
- Meta‐analysis: anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients. Ann Intern Med. 2007; 46(4):278–288. , , , , .
- A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score. J Thromb Haemost. 2010;8(11):2450–2457. , , , et al.
- Medical admission order sets to improve deep vein thrombosis prophylaxis rates and other outcomes. J Hosp Med. 2009;4(2):81–89. , , , .
- Medical admission order sets to improve deep vein thrombosis prevention: a model for others or a prescription for mediocrity? J Hosp Med. 2009;4(2):77–80. .
- Designing and implementing effective VTE prevention protocols: lessons from collaboratives. J Thromb Thrombolysis. 2010;29(2):159–166. , .
- Optimizing prevention of hospital acquired venous thromboembolism: prospective validation of a VTE risk assessment model. J Hosp Med. 2010;5(1):10–18. , , , et al.
- 2011 John M. Eisenberg Patient Safety and Quality Awards. Mentored implementation: building leaders and achieving results through a collaborative improvement model. Innovation in patient safety and quality at the national level. Jt Comm J Qual Patient Saf. 2012;38(7):301–310. , , , et al.
- NHS National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. NICE Clinical Guideline 92. 2010. Available at: http://www.nice.org.uk/guidance/CG92. Accessed April 18, 2013.
- Reliability of a point‐based VTE risk assessment tool in the hands of medical residents. J Hosp Med. 2011;6:195–201. , , , , .
- A validation of a retrospective venous thromboembolism risk scoring method. Ann Surg. 2010;251(2):344–350. , , , , , .
- Risk assessment models for thromboprophylaxis of medical patients. Thromb Res. 2012;129:127–132. , , , .
- Risk‐assessment models for predicting venous thromboembolism among hospitalized non‐surgical patients: a systematic review. J Thromb Thrombolysis. 2013;35:67–80. , , , , .
- The use of weighted and scored risk assessment models for venous thromboembolism. Thromb Haemost. 2012;108(6):1072–1076. , , .
- Lessons from the Johns Hopkins Multi‐Disciplinary Venous Thromboembolism (VTE) Prevention Collaborative. BMJ. 2012;344:e3935. , , , et al.
Recent onset of rash, dehydration, and nonbloody diarrhea in an elderly man
An 80-year-old Hawaiian man of Chinese ancestry arrives at the emergency department with diarrhea and dehydration. You are called to admit him for acute renal failure. On entering the patient’s room, you note that he has a diffuse maculopapular rash and is wheezing.
Twenty-one months earlier, the patient suffered his first episode of gout. Since that time, he has been asymptomatic. Two months ago, his primary care physician obtained a uric acid level and found it elevated at 10.6 mg/dL. She started the patient on allopurinol 300 mg PO daily.
Twenty days ago (approximately 6 weeks after initiation of allopurinol), the rash developed along with generalized pruritus. The patient’s primary care physician referred him to a dermatologist for skin biopsy, and he discontinued allopurinol 11 days ago.
Just in the past week, the patient began to experience a metallic taste in his mouth, as well as anorexia, malaise, chills, dysuria, and nonbloody diarrhea. He became nauseous and decreased his oral intake, which led to dehydration and progressive weakness.
Additional medical history
- The patient’s medical history is significant for renal insufficiency, type 2 diabetes mellitus, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, chronic nasal allergies, benign prostatic hypertrophy, osteoarthritis, and gout.
- He is taking the following medications: fluticasone inhalant 110 mcg daily; fluticasone propionate one spray in both nostrils daily; montelukast 10 mg PO daily; irbesartan 300 mg PO daily; amlodipine 5 mg PO daily; glyburide 2.5 mg PO BID; triamterene/hydrochlorothiazide 37.5/25 mg PO QOD; albuterol 90 mcg 2 puffs q6h prn; terazosin 2 mg PO qhs; simvastatin 40 mg PO daily; azelastine 137 mcg 1 spray in both nostrils prn; meclizine 25 mg PO daily prn; fexofenadine 150 mg PO qPM; cyclobenzaprine 10 mg PO qhs prn; and hydrocodone/acetamino- phen 5/500 mg 2 tabs PO daily prn.
Social history
- The patient recently arrived from Hawaii to visit his wife’s family.
- He does not drink alcohol, but he smokes 4 cigarettes a day.
Review of systems
- A review of systems is negative for the following: fever, sick contacts, history of renal calculi, hemoptysis, ocular or ENT symptoms, history of hepatic disease, peripheral neuropathy, and neurologic symptoms.
Physical examination
- The patient is alert and cooperative.
- Temperature is 97.9oF, blood pressure 110/52 mm Hg, pulse 112 beats per minute, respiratory rate 16 breaths per minute, oxygen saturation 96% on room air.
- Mucous membranes are dry.
- Auscultation of the heart is normal.
- Significant wheezing is present in bilateral lung fields, but requiring no use of accessory muscles during respiration.
- Abdominal exam is remarkable only for obesity.
- Trace pitting edema is present in both lower extremities.
- The maculopapular rash is diffuse and nonblanching. Scaling on the trunk, areas of erythema below the umbilicus, and coalescing macular lesions on bilateral lower extremities are present.
- Joints are not swollen or tender, and there are no tophi.
- There are no focal neurologic deficits, and deep tendon reflexes are normal.
Laboratory studies completed in the ED
- Blood urea nitrogen, 112 mg/dL ; creatinine, 3 mg/dL ; glomerular filtration rate (GFR), 22 mL/min (baseline ratio of blood urea nitrogen/creatinine, 36:1.57; baseline GFR, 43 mL/min)
- White blood cell count, 15 k/uL
- Hemoglobin, 14.3 g/dL ; hematocrit, 43.6%; platelet count, 307/uL
- Alanine aminotransferase and aspartate aminotransferase, 177 and 139 IU/L, respectively
- Direct, indirect, and total bilirubin, 0.60, 1.19, and 1.79 mg/dL, respectively
- Serum eosinophils, 22% (normal <6%)
- Erythrocyte sedimentation rate, 50 mm/h.
Radiology
- Chest radiographs (posterior-anterior, lateral) show a bilateral process consistent with atelectasis or lung scarring.
- Noncontrast computed tomography (CT) of the thorax confirms parenchymal scarring but no acute process.
- Hepatic sonography reveals increased echogenicity of the liver parenchyma consistent with an acute hepatocellular process.
- Magnetic resonance imaging (MRI) of the abdomen shows a diffuse process in the liver with trace parahepatic ascites.
- Renal ultrasound shows bilateral renal cysts with no hydronephrosis or urolithiasis.
- Cardiac echocardiography reveals left ventricular hypertrophy but normal ejection fraction.
- Noncontrast CT (head) and MRI (brain) show an acute right frontoparietal cerebrovascular accident and an old lacunar infarct.
Dermatologist’s report
- A skin biopsy reveals lymphocytic perivascular infiltrate with scattered eosinophils and mild spongiosis consistent with vasculitis.
Follow-up laboratory data
- Acute hepatitis panel is negative
- Uric acid, 13.8 mg/dL
- Urine eosinophils, 31% (normal <1%)
- Anti-neutrophil cytoplasmic antibody IgG, 1:40 mildly elevated (normal<1:20)
- Anti-nuclear antibody (ANA) IgG, none
- Glycosylated hemoglobin, 7.1%
- High-sensitivity C-reactive protein, 207.96 mg/L (>10 mg/L is very high)
In summary, this patient’s erythematous rash is a biopsy-confirmed vasculitis. Additional findings are hepatitis, acute on chronic renal failure, eosinophilia, and leukocytosis.
Q/ What is your presumptive diagnosis?
Allopurinol hypersensitivity syndrome
Allopurinol hypersensitivity syndrome (AHS) is a diffuse vasculitis induced by a type III hypersensitivity reaction, possibly to oxypurinol, allopurinol’s toxic metabolite. The exact pathophysiology is unknown, but oxypurinol levels correlate positively with the risk of AHS.1 Thiazides may increase oxypurinol levels.2
Signs and symptoms of AHS include fever, erythematous skin rash, eosinophilia, hepatitis, progressive renal insufficiency, and leukocytosis. Case reports have also attributed septic shock, myocardial infarction, and Guillain-Barré syndrome to AHS.3-6 The incidence of AHS is 0.1% to 0.4% of patients treated with allopurinol; mortality approaches 25%.1
Q/ What are the diagnostic criteria for AHS?
Singer and Wallace have outlined diagnostic criteria for AHS,7 the first being a clear history of exposure to allopurinol.
Second, the clinical profile usually takes one of the following forms:
- The patient exhibits at least 2 of the following major features: worsening renal function, acute hepatocellular injury, or a rash (toxic epidermal necrolysis, erythema multiforme, or diffuse maculopapular or exfoliative dermatitis) or
- The patient exhibits just one of the major features and at least one of the following minor features: fever, eosinophilia, or leukocytosis.
Third, there is no history of exposure to another drug that may cause a similar clinical picture.
Q/ What is the accepted treatment for ahS?
Although there is no well-established treatment plan, the standard of care is to discontinue allopurinol, administer parenteral corticosteroids followed by oral taper, and offer supportive management. Desensitization protocols are difficult and hypersensitivity reactions may recur. Early withdrawal of steroids has been reported to result in recurrence of symptoms. However, no strong data exist for determining an optimal length of corticosteroid therapy, or the number of days that constitutes “early” withdrawal of steroids. Mortality is high, even with seemingly adequate treatment.
Q/ Which patients are most at risk for ahS?
Definite risk factors for AHS include recent onset of allopurinol therapy, the presence of HLA-B5801 allele in patients of Han Chinese and European ancestry, and chronic kidney disease.1,8,9 Suggested risk factors include concomitant use of thiazide diuretics with allopurinol, treatment of asymptomatic hyperuricemia, and high allopurinol dose relative to renal function.
Q/ What are the indications for allopurinol therapy?
Indications for allopurinol therapy:1,10
- Failure of uricosuric drugs or contraindications to their use
- Frequent attacks of gouty arthritis (≥3 per year)
- Nephrolithiasis
- Marked overproduction of urate, such as seen in tumor lysis syndrome
- The presence of tophi.
For patients with appropriate indications for allopurinol therapy, treat with the minimum effective dose. Initiation of allopurinol is controversial for a patient with a single lifetime episode of gout. However, most patients with one episode of gout will develop recurrent gout.8
In patients with creatinine clearance >60 mL/min, allopurinol is usually started at 100 mg oral daily and titrated every 2 to 3 weeks until reaching the desired effectiveness.8 One retrospective study suggests that initiating allopurinol at a dose of 1.5 mg per unit of estimated GFR may reduce the risk of AHS.11
Our patient’s case: Treatment, discharge, readmission
With our patient, we started intravenous normal saline fluid boluses and parenteral methylprednisolone, 60 mg q6h. We discontinued triamterene/hydrochlorothiazide due to his hyperuricemia, and irbesartan and glyburide due to renal failure. Basal and rapid-acting insulins maintained good glycemic control. To control his wheezing and dyspnea, we began albuterol/ipratropium nebulizer treatments and oxygen delivery via nasal cannula. Nephrology, pulmonology, and rheumatology consultants agreed with these management decisions.
Over the next 9 days, the patient’s renal function improved and his rash started to resolve. His wheezing fluctuated but persisted throughout the hospital stay. We stopped nasal oxygen delivery, and his oxygen saturation remained normal (96%-98%) on room air. He was subsequently discharged in stable condition on a 2-week prednisone taper starting at 30 mg bid.
Thirteen days later, he was readmitted with a right frontoparietal cerebrovascular accident (CVA). He developed respiratory distress, which led to respiratory arrest, and was ventilated. He became hypotensive, lapsed into shock, and died a few days later (approximately one month after initial presentation).
The appropriate use of allopurinol—a second look
This case raised many questions for our inpatient team concerning not just AHS, but the appropriate use and dosing of allopurinol. Allopurinol is widely used for hyperuricemia and gout because it is effective for all causes of hyperuricemia and is inexpensive. Given that 3.9%12 of the general population has gout and that its prevalence has increased with rising rates of obesity, the importance of AHS is not abstract.
Revisiting initial treatment choices. Our patient was at risk for this syndrome due to his Chinese ancestry, recent onset of allopurinol therapy, concomitant use of triamterene/hydrochlorothiazide, and impaired renal function. Although his uric acid level was >10 mg/dL when treatment was started, his risk factors may have precluded initiation of allopurinol. Furthermore, the prescribed dose of allopurinol (300 mg) was too high for his baseline GFR; 100 mg daily would have been more appropriate. It could be argued that hydrochlorothiazide would not be an antihypertensive of choice due to its hyperuricemic effects. Switching the thiazide to a loop diuretic would offer no benefit, because loop diuretics also cause hyperuricemia. (More on which antihypertensive agent would have been appropriate in a bit.)
The role of AHS in the patient’s death is unclear. He was at high risk for stroke considering his age, comorbidities, and evidence of an old lacunar infarct. Myocardial infarctions have been reported as one cause of death in AHS, but we have found no reports of associated stroke. However, the temporal proximity of the CVA suggests a contributing effect of AHS. The adequacy of treatment is also brought into question. Early withdrawal of glucocorticoids can be associated with relapse of AHS; in retrospect, the prednisone dose may have been too low or the taper too short, or both.
Therapeutic alternatives to allopurinol were available. The most appropriate initial option for this patient likely was no pharmacologic intervention at all but a focus on weight loss and diet. The risk of gouty attacks in men increases as body mass index rises above normal (≥25 kg/m2) and decreases with weight loss. Lower calorie diets with decreased saturated fat, higher complex carbohydrates, and allowed proteins (low-fat dairy products) are more palatable and more effective than strict low-purine diets.
A urate-lowering antihypertensive may have been a better option—specifically, losartan rather than irbesartan and triamterene/hydrochlorothiazide.8,13 Losartan has uricosuric properties at the 50-mg dose.14 When compared in different studies with irbesartan, enalapril, and candesartan, losartan alone lowered serum urate levels. Increasing losartan to 100 mg could provide better hypertensive control but has not been found to lower urate levels more dramatically than the lower dose.13
Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been found to blunt the urate-elevating effects of thiazides. Therefore, if the patient’s blood pressure was not adequately controlled on losartan alone, the combination of losartan/hydrochlorothiazide would be a reasonable choice because minimal or no change in serum uric acid levels would be expected.15
Febuxostat, a nonpurine selective inhibitor of xanthine oxidase, is a potential alternative to allopurinol in patients with gout. It is a more potent urate-lowering agent than allopurinol and can be used without dosage reduction in mild (creatinine clearance [CrCl], 60-89 mL/min) to moderate (CrCl, 30-59 mL/ min) renal insufficiency. Febuxostat is metabolized primarily in the liver—in contrast to allopurinol, which is excreted by the kidneys—and may increase liver transaminase levels.10 Although febuxostat was not available at the time our patient developed AHS, it would not have been indicated in asymptomatic hyperuricemia.
This compelling case reminds us to carefully consider the indications and risk factors in using allopurinol, and to be aware of the rare but sometimes devastating consequences of this commonly used drug.
CORRESPONDENCE
Tahirah Tyrell, MD, Rochester General Medical Group, 1425 Portland Avenue, Rochester, NY 14621;
[email protected].
1. Lee HY, Ariyasinghe J, Thirumoorthy T. Allopurinol hypersensitivity syndrome: a preventable severe cutaneous adverse reaction? Singapore Med J. 2008;49:384-387.
2. Markel A. Allopurinol hypersensitivity and DRESS syndrome. Am J Med. 2008;121:e25.
3. Koike K, et al. Adverse reaction case reports. React Wkly. 2008 Sept 6;1218:5.
4. Mete N, Yilmaz F, et al. Adverse reaction case reports. React Wkly. 2004 June 26;1007:7.
5. Benito-León J, Porta-Etessam J. Guillain-Barré syndrome and allopurinol- induced hypersensitivity. Eur Neurol. 2001;45:186-187.
6. Makar-Ausperger KMA. Allopurinol/furosemide. Hypersensitivity syndrome: case report. Reactions Wkly. 2007 Oct 13;1173:5.
7. Singer JZ, Wallace SL. The allopurinol hypersensitivity syndrome. Unnecessary morbidity and mortality. Arthritis Rheum. 1986; 29: 82-87.
8. Becker M. Prevention of recurrent gout. UpToDate. April 10, 2013. Available at: http://www.uptodate.com/contents/prevention-ofrecurrent- gout?detectedLanguage=en&source=search_result&s earch=Prevention+of+recurrent+gout&selectedTitle=1%7E8&pr ovider=noProvider. Accessed August 1, 2013.
9. Ramasamy SN, Korb-Wells CS, Kannangara DR, et al. Allopurinol hypersensitivity: a systematic review of all published cases, 1950- 2012. Drug Saf. 2013;July 20. [Epub ahead of print].
10. Moreland LW. Febuxostat–treatment for hyperuricemia and gout? N Engl J Med. 2005;353:2505-2507.
11. Stamp LK, Taylor WJ, Jones PB, et al. Starting dose is a risk factor for allopurinol hypersensitivity syndrome: a proposed safe starting dose of allopurinol. Arthritis Rheum. 2012;64:2529-2536.
12. Zhu Y, Pandya BJ, Choi HK. Prevalence of gout and hyperuricemia in the US general population: the National Health and Nutrition Examination Survey 2007-2008. Arthritis Rheum. 2011;63: 3136-3141.
13. Würzner G, Gerster JC, Chiolero A, et al. Comparative effects of losartan and irbesartan on serum uric acid in hypertensive patients with hyperuricemia and gout. J Hypertens. 2001;19:1855-1860.
14. Terkeltaub RA. Clinical practice. gout. N Engl J Med. 2003;349:1647-1655.
15. Manolis AJ, Grossman E, Jelakovic B, et al. Effects of losartan and candesartan monotherapy and losartan/hydrochlorothiazide combination therapy in patients with mild to moderate hypertension. Losartan Trial Investigators. Clin Ther. 2000;22:1186-1203.
An 80-year-old Hawaiian man of Chinese ancestry arrives at the emergency department with diarrhea and dehydration. You are called to admit him for acute renal failure. On entering the patient’s room, you note that he has a diffuse maculopapular rash and is wheezing.
Twenty-one months earlier, the patient suffered his first episode of gout. Since that time, he has been asymptomatic. Two months ago, his primary care physician obtained a uric acid level and found it elevated at 10.6 mg/dL. She started the patient on allopurinol 300 mg PO daily.
Twenty days ago (approximately 6 weeks after initiation of allopurinol), the rash developed along with generalized pruritus. The patient’s primary care physician referred him to a dermatologist for skin biopsy, and he discontinued allopurinol 11 days ago.
Just in the past week, the patient began to experience a metallic taste in his mouth, as well as anorexia, malaise, chills, dysuria, and nonbloody diarrhea. He became nauseous and decreased his oral intake, which led to dehydration and progressive weakness.
Additional medical history
- The patient’s medical history is significant for renal insufficiency, type 2 diabetes mellitus, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, chronic nasal allergies, benign prostatic hypertrophy, osteoarthritis, and gout.
- He is taking the following medications: fluticasone inhalant 110 mcg daily; fluticasone propionate one spray in both nostrils daily; montelukast 10 mg PO daily; irbesartan 300 mg PO daily; amlodipine 5 mg PO daily; glyburide 2.5 mg PO BID; triamterene/hydrochlorothiazide 37.5/25 mg PO QOD; albuterol 90 mcg 2 puffs q6h prn; terazosin 2 mg PO qhs; simvastatin 40 mg PO daily; azelastine 137 mcg 1 spray in both nostrils prn; meclizine 25 mg PO daily prn; fexofenadine 150 mg PO qPM; cyclobenzaprine 10 mg PO qhs prn; and hydrocodone/acetamino- phen 5/500 mg 2 tabs PO daily prn.
Social history
- The patient recently arrived from Hawaii to visit his wife’s family.
- He does not drink alcohol, but he smokes 4 cigarettes a day.
Review of systems
- A review of systems is negative for the following: fever, sick contacts, history of renal calculi, hemoptysis, ocular or ENT symptoms, history of hepatic disease, peripheral neuropathy, and neurologic symptoms.
Physical examination
- The patient is alert and cooperative.
- Temperature is 97.9oF, blood pressure 110/52 mm Hg, pulse 112 beats per minute, respiratory rate 16 breaths per minute, oxygen saturation 96% on room air.
- Mucous membranes are dry.
- Auscultation of the heart is normal.
- Significant wheezing is present in bilateral lung fields, but requiring no use of accessory muscles during respiration.
- Abdominal exam is remarkable only for obesity.
- Trace pitting edema is present in both lower extremities.
- The maculopapular rash is diffuse and nonblanching. Scaling on the trunk, areas of erythema below the umbilicus, and coalescing macular lesions on bilateral lower extremities are present.
- Joints are not swollen or tender, and there are no tophi.
- There are no focal neurologic deficits, and deep tendon reflexes are normal.
Laboratory studies completed in the ED
- Blood urea nitrogen, 112 mg/dL ; creatinine, 3 mg/dL ; glomerular filtration rate (GFR), 22 mL/min (baseline ratio of blood urea nitrogen/creatinine, 36:1.57; baseline GFR, 43 mL/min)
- White blood cell count, 15 k/uL
- Hemoglobin, 14.3 g/dL ; hematocrit, 43.6%; platelet count, 307/uL
- Alanine aminotransferase and aspartate aminotransferase, 177 and 139 IU/L, respectively
- Direct, indirect, and total bilirubin, 0.60, 1.19, and 1.79 mg/dL, respectively
- Serum eosinophils, 22% (normal <6%)
- Erythrocyte sedimentation rate, 50 mm/h.
Radiology
- Chest radiographs (posterior-anterior, lateral) show a bilateral process consistent with atelectasis or lung scarring.
- Noncontrast computed tomography (CT) of the thorax confirms parenchymal scarring but no acute process.
- Hepatic sonography reveals increased echogenicity of the liver parenchyma consistent with an acute hepatocellular process.
- Magnetic resonance imaging (MRI) of the abdomen shows a diffuse process in the liver with trace parahepatic ascites.
- Renal ultrasound shows bilateral renal cysts with no hydronephrosis or urolithiasis.
- Cardiac echocardiography reveals left ventricular hypertrophy but normal ejection fraction.
- Noncontrast CT (head) and MRI (brain) show an acute right frontoparietal cerebrovascular accident and an old lacunar infarct.
Dermatologist’s report
- A skin biopsy reveals lymphocytic perivascular infiltrate with scattered eosinophils and mild spongiosis consistent with vasculitis.
Follow-up laboratory data
- Acute hepatitis panel is negative
- Uric acid, 13.8 mg/dL
- Urine eosinophils, 31% (normal <1%)
- Anti-neutrophil cytoplasmic antibody IgG, 1:40 mildly elevated (normal<1:20)
- Anti-nuclear antibody (ANA) IgG, none
- Glycosylated hemoglobin, 7.1%
- High-sensitivity C-reactive protein, 207.96 mg/L (>10 mg/L is very high)
In summary, this patient’s erythematous rash is a biopsy-confirmed vasculitis. Additional findings are hepatitis, acute on chronic renal failure, eosinophilia, and leukocytosis.
Q/ What is your presumptive diagnosis?
Allopurinol hypersensitivity syndrome
Allopurinol hypersensitivity syndrome (AHS) is a diffuse vasculitis induced by a type III hypersensitivity reaction, possibly to oxypurinol, allopurinol’s toxic metabolite. The exact pathophysiology is unknown, but oxypurinol levels correlate positively with the risk of AHS.1 Thiazides may increase oxypurinol levels.2
Signs and symptoms of AHS include fever, erythematous skin rash, eosinophilia, hepatitis, progressive renal insufficiency, and leukocytosis. Case reports have also attributed septic shock, myocardial infarction, and Guillain-Barré syndrome to AHS.3-6 The incidence of AHS is 0.1% to 0.4% of patients treated with allopurinol; mortality approaches 25%.1
Q/ What are the diagnostic criteria for AHS?
Singer and Wallace have outlined diagnostic criteria for AHS,7 the first being a clear history of exposure to allopurinol.
Second, the clinical profile usually takes one of the following forms:
- The patient exhibits at least 2 of the following major features: worsening renal function, acute hepatocellular injury, or a rash (toxic epidermal necrolysis, erythema multiforme, or diffuse maculopapular or exfoliative dermatitis) or
- The patient exhibits just one of the major features and at least one of the following minor features: fever, eosinophilia, or leukocytosis.
Third, there is no history of exposure to another drug that may cause a similar clinical picture.
Q/ What is the accepted treatment for ahS?
Although there is no well-established treatment plan, the standard of care is to discontinue allopurinol, administer parenteral corticosteroids followed by oral taper, and offer supportive management. Desensitization protocols are difficult and hypersensitivity reactions may recur. Early withdrawal of steroids has been reported to result in recurrence of symptoms. However, no strong data exist for determining an optimal length of corticosteroid therapy, or the number of days that constitutes “early” withdrawal of steroids. Mortality is high, even with seemingly adequate treatment.
Q/ Which patients are most at risk for ahS?
Definite risk factors for AHS include recent onset of allopurinol therapy, the presence of HLA-B5801 allele in patients of Han Chinese and European ancestry, and chronic kidney disease.1,8,9 Suggested risk factors include concomitant use of thiazide diuretics with allopurinol, treatment of asymptomatic hyperuricemia, and high allopurinol dose relative to renal function.
Q/ What are the indications for allopurinol therapy?
Indications for allopurinol therapy:1,10
- Failure of uricosuric drugs or contraindications to their use
- Frequent attacks of gouty arthritis (≥3 per year)
- Nephrolithiasis
- Marked overproduction of urate, such as seen in tumor lysis syndrome
- The presence of tophi.
For patients with appropriate indications for allopurinol therapy, treat with the minimum effective dose. Initiation of allopurinol is controversial for a patient with a single lifetime episode of gout. However, most patients with one episode of gout will develop recurrent gout.8
In patients with creatinine clearance >60 mL/min, allopurinol is usually started at 100 mg oral daily and titrated every 2 to 3 weeks until reaching the desired effectiveness.8 One retrospective study suggests that initiating allopurinol at a dose of 1.5 mg per unit of estimated GFR may reduce the risk of AHS.11
Our patient’s case: Treatment, discharge, readmission
With our patient, we started intravenous normal saline fluid boluses and parenteral methylprednisolone, 60 mg q6h. We discontinued triamterene/hydrochlorothiazide due to his hyperuricemia, and irbesartan and glyburide due to renal failure. Basal and rapid-acting insulins maintained good glycemic control. To control his wheezing and dyspnea, we began albuterol/ipratropium nebulizer treatments and oxygen delivery via nasal cannula. Nephrology, pulmonology, and rheumatology consultants agreed with these management decisions.
Over the next 9 days, the patient’s renal function improved and his rash started to resolve. His wheezing fluctuated but persisted throughout the hospital stay. We stopped nasal oxygen delivery, and his oxygen saturation remained normal (96%-98%) on room air. He was subsequently discharged in stable condition on a 2-week prednisone taper starting at 30 mg bid.
Thirteen days later, he was readmitted with a right frontoparietal cerebrovascular accident (CVA). He developed respiratory distress, which led to respiratory arrest, and was ventilated. He became hypotensive, lapsed into shock, and died a few days later (approximately one month after initial presentation).
The appropriate use of allopurinol—a second look
This case raised many questions for our inpatient team concerning not just AHS, but the appropriate use and dosing of allopurinol. Allopurinol is widely used for hyperuricemia and gout because it is effective for all causes of hyperuricemia and is inexpensive. Given that 3.9%12 of the general population has gout and that its prevalence has increased with rising rates of obesity, the importance of AHS is not abstract.
Revisiting initial treatment choices. Our patient was at risk for this syndrome due to his Chinese ancestry, recent onset of allopurinol therapy, concomitant use of triamterene/hydrochlorothiazide, and impaired renal function. Although his uric acid level was >10 mg/dL when treatment was started, his risk factors may have precluded initiation of allopurinol. Furthermore, the prescribed dose of allopurinol (300 mg) was too high for his baseline GFR; 100 mg daily would have been more appropriate. It could be argued that hydrochlorothiazide would not be an antihypertensive of choice due to its hyperuricemic effects. Switching the thiazide to a loop diuretic would offer no benefit, because loop diuretics also cause hyperuricemia. (More on which antihypertensive agent would have been appropriate in a bit.)
The role of AHS in the patient’s death is unclear. He was at high risk for stroke considering his age, comorbidities, and evidence of an old lacunar infarct. Myocardial infarctions have been reported as one cause of death in AHS, but we have found no reports of associated stroke. However, the temporal proximity of the CVA suggests a contributing effect of AHS. The adequacy of treatment is also brought into question. Early withdrawal of glucocorticoids can be associated with relapse of AHS; in retrospect, the prednisone dose may have been too low or the taper too short, or both.
Therapeutic alternatives to allopurinol were available. The most appropriate initial option for this patient likely was no pharmacologic intervention at all but a focus on weight loss and diet. The risk of gouty attacks in men increases as body mass index rises above normal (≥25 kg/m2) and decreases with weight loss. Lower calorie diets with decreased saturated fat, higher complex carbohydrates, and allowed proteins (low-fat dairy products) are more palatable and more effective than strict low-purine diets.
A urate-lowering antihypertensive may have been a better option—specifically, losartan rather than irbesartan and triamterene/hydrochlorothiazide.8,13 Losartan has uricosuric properties at the 50-mg dose.14 When compared in different studies with irbesartan, enalapril, and candesartan, losartan alone lowered serum urate levels. Increasing losartan to 100 mg could provide better hypertensive control but has not been found to lower urate levels more dramatically than the lower dose.13
Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been found to blunt the urate-elevating effects of thiazides. Therefore, if the patient’s blood pressure was not adequately controlled on losartan alone, the combination of losartan/hydrochlorothiazide would be a reasonable choice because minimal or no change in serum uric acid levels would be expected.15
Febuxostat, a nonpurine selective inhibitor of xanthine oxidase, is a potential alternative to allopurinol in patients with gout. It is a more potent urate-lowering agent than allopurinol and can be used without dosage reduction in mild (creatinine clearance [CrCl], 60-89 mL/min) to moderate (CrCl, 30-59 mL/ min) renal insufficiency. Febuxostat is metabolized primarily in the liver—in contrast to allopurinol, which is excreted by the kidneys—and may increase liver transaminase levels.10 Although febuxostat was not available at the time our patient developed AHS, it would not have been indicated in asymptomatic hyperuricemia.
This compelling case reminds us to carefully consider the indications and risk factors in using allopurinol, and to be aware of the rare but sometimes devastating consequences of this commonly used drug.
CORRESPONDENCE
Tahirah Tyrell, MD, Rochester General Medical Group, 1425 Portland Avenue, Rochester, NY 14621;
[email protected].
An 80-year-old Hawaiian man of Chinese ancestry arrives at the emergency department with diarrhea and dehydration. You are called to admit him for acute renal failure. On entering the patient’s room, you note that he has a diffuse maculopapular rash and is wheezing.
Twenty-one months earlier, the patient suffered his first episode of gout. Since that time, he has been asymptomatic. Two months ago, his primary care physician obtained a uric acid level and found it elevated at 10.6 mg/dL. She started the patient on allopurinol 300 mg PO daily.
Twenty days ago (approximately 6 weeks after initiation of allopurinol), the rash developed along with generalized pruritus. The patient’s primary care physician referred him to a dermatologist for skin biopsy, and he discontinued allopurinol 11 days ago.
Just in the past week, the patient began to experience a metallic taste in his mouth, as well as anorexia, malaise, chills, dysuria, and nonbloody diarrhea. He became nauseous and decreased his oral intake, which led to dehydration and progressive weakness.
Additional medical history
- The patient’s medical history is significant for renal insufficiency, type 2 diabetes mellitus, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, chronic nasal allergies, benign prostatic hypertrophy, osteoarthritis, and gout.
- He is taking the following medications: fluticasone inhalant 110 mcg daily; fluticasone propionate one spray in both nostrils daily; montelukast 10 mg PO daily; irbesartan 300 mg PO daily; amlodipine 5 mg PO daily; glyburide 2.5 mg PO BID; triamterene/hydrochlorothiazide 37.5/25 mg PO QOD; albuterol 90 mcg 2 puffs q6h prn; terazosin 2 mg PO qhs; simvastatin 40 mg PO daily; azelastine 137 mcg 1 spray in both nostrils prn; meclizine 25 mg PO daily prn; fexofenadine 150 mg PO qPM; cyclobenzaprine 10 mg PO qhs prn; and hydrocodone/acetamino- phen 5/500 mg 2 tabs PO daily prn.
Social history
- The patient recently arrived from Hawaii to visit his wife’s family.
- He does not drink alcohol, but he smokes 4 cigarettes a day.
Review of systems
- A review of systems is negative for the following: fever, sick contacts, history of renal calculi, hemoptysis, ocular or ENT symptoms, history of hepatic disease, peripheral neuropathy, and neurologic symptoms.
Physical examination
- The patient is alert and cooperative.
- Temperature is 97.9oF, blood pressure 110/52 mm Hg, pulse 112 beats per minute, respiratory rate 16 breaths per minute, oxygen saturation 96% on room air.
- Mucous membranes are dry.
- Auscultation of the heart is normal.
- Significant wheezing is present in bilateral lung fields, but requiring no use of accessory muscles during respiration.
- Abdominal exam is remarkable only for obesity.
- Trace pitting edema is present in both lower extremities.
- The maculopapular rash is diffuse and nonblanching. Scaling on the trunk, areas of erythema below the umbilicus, and coalescing macular lesions on bilateral lower extremities are present.
- Joints are not swollen or tender, and there are no tophi.
- There are no focal neurologic deficits, and deep tendon reflexes are normal.
Laboratory studies completed in the ED
- Blood urea nitrogen, 112 mg/dL ; creatinine, 3 mg/dL ; glomerular filtration rate (GFR), 22 mL/min (baseline ratio of blood urea nitrogen/creatinine, 36:1.57; baseline GFR, 43 mL/min)
- White blood cell count, 15 k/uL
- Hemoglobin, 14.3 g/dL ; hematocrit, 43.6%; platelet count, 307/uL
- Alanine aminotransferase and aspartate aminotransferase, 177 and 139 IU/L, respectively
- Direct, indirect, and total bilirubin, 0.60, 1.19, and 1.79 mg/dL, respectively
- Serum eosinophils, 22% (normal <6%)
- Erythrocyte sedimentation rate, 50 mm/h.
Radiology
- Chest radiographs (posterior-anterior, lateral) show a bilateral process consistent with atelectasis or lung scarring.
- Noncontrast computed tomography (CT) of the thorax confirms parenchymal scarring but no acute process.
- Hepatic sonography reveals increased echogenicity of the liver parenchyma consistent with an acute hepatocellular process.
- Magnetic resonance imaging (MRI) of the abdomen shows a diffuse process in the liver with trace parahepatic ascites.
- Renal ultrasound shows bilateral renal cysts with no hydronephrosis or urolithiasis.
- Cardiac echocardiography reveals left ventricular hypertrophy but normal ejection fraction.
- Noncontrast CT (head) and MRI (brain) show an acute right frontoparietal cerebrovascular accident and an old lacunar infarct.
Dermatologist’s report
- A skin biopsy reveals lymphocytic perivascular infiltrate with scattered eosinophils and mild spongiosis consistent with vasculitis.
Follow-up laboratory data
- Acute hepatitis panel is negative
- Uric acid, 13.8 mg/dL
- Urine eosinophils, 31% (normal <1%)
- Anti-neutrophil cytoplasmic antibody IgG, 1:40 mildly elevated (normal<1:20)
- Anti-nuclear antibody (ANA) IgG, none
- Glycosylated hemoglobin, 7.1%
- High-sensitivity C-reactive protein, 207.96 mg/L (>10 mg/L is very high)
In summary, this patient’s erythematous rash is a biopsy-confirmed vasculitis. Additional findings are hepatitis, acute on chronic renal failure, eosinophilia, and leukocytosis.
Q/ What is your presumptive diagnosis?
Allopurinol hypersensitivity syndrome
Allopurinol hypersensitivity syndrome (AHS) is a diffuse vasculitis induced by a type III hypersensitivity reaction, possibly to oxypurinol, allopurinol’s toxic metabolite. The exact pathophysiology is unknown, but oxypurinol levels correlate positively with the risk of AHS.1 Thiazides may increase oxypurinol levels.2
Signs and symptoms of AHS include fever, erythematous skin rash, eosinophilia, hepatitis, progressive renal insufficiency, and leukocytosis. Case reports have also attributed septic shock, myocardial infarction, and Guillain-Barré syndrome to AHS.3-6 The incidence of AHS is 0.1% to 0.4% of patients treated with allopurinol; mortality approaches 25%.1
Q/ What are the diagnostic criteria for AHS?
Singer and Wallace have outlined diagnostic criteria for AHS,7 the first being a clear history of exposure to allopurinol.
Second, the clinical profile usually takes one of the following forms:
- The patient exhibits at least 2 of the following major features: worsening renal function, acute hepatocellular injury, or a rash (toxic epidermal necrolysis, erythema multiforme, or diffuse maculopapular or exfoliative dermatitis) or
- The patient exhibits just one of the major features and at least one of the following minor features: fever, eosinophilia, or leukocytosis.
Third, there is no history of exposure to another drug that may cause a similar clinical picture.
Q/ What is the accepted treatment for ahS?
Although there is no well-established treatment plan, the standard of care is to discontinue allopurinol, administer parenteral corticosteroids followed by oral taper, and offer supportive management. Desensitization protocols are difficult and hypersensitivity reactions may recur. Early withdrawal of steroids has been reported to result in recurrence of symptoms. However, no strong data exist for determining an optimal length of corticosteroid therapy, or the number of days that constitutes “early” withdrawal of steroids. Mortality is high, even with seemingly adequate treatment.
Q/ Which patients are most at risk for ahS?
Definite risk factors for AHS include recent onset of allopurinol therapy, the presence of HLA-B5801 allele in patients of Han Chinese and European ancestry, and chronic kidney disease.1,8,9 Suggested risk factors include concomitant use of thiazide diuretics with allopurinol, treatment of asymptomatic hyperuricemia, and high allopurinol dose relative to renal function.
Q/ What are the indications for allopurinol therapy?
Indications for allopurinol therapy:1,10
- Failure of uricosuric drugs or contraindications to their use
- Frequent attacks of gouty arthritis (≥3 per year)
- Nephrolithiasis
- Marked overproduction of urate, such as seen in tumor lysis syndrome
- The presence of tophi.
For patients with appropriate indications for allopurinol therapy, treat with the minimum effective dose. Initiation of allopurinol is controversial for a patient with a single lifetime episode of gout. However, most patients with one episode of gout will develop recurrent gout.8
In patients with creatinine clearance >60 mL/min, allopurinol is usually started at 100 mg oral daily and titrated every 2 to 3 weeks until reaching the desired effectiveness.8 One retrospective study suggests that initiating allopurinol at a dose of 1.5 mg per unit of estimated GFR may reduce the risk of AHS.11
Our patient’s case: Treatment, discharge, readmission
With our patient, we started intravenous normal saline fluid boluses and parenteral methylprednisolone, 60 mg q6h. We discontinued triamterene/hydrochlorothiazide due to his hyperuricemia, and irbesartan and glyburide due to renal failure. Basal and rapid-acting insulins maintained good glycemic control. To control his wheezing and dyspnea, we began albuterol/ipratropium nebulizer treatments and oxygen delivery via nasal cannula. Nephrology, pulmonology, and rheumatology consultants agreed with these management decisions.
Over the next 9 days, the patient’s renal function improved and his rash started to resolve. His wheezing fluctuated but persisted throughout the hospital stay. We stopped nasal oxygen delivery, and his oxygen saturation remained normal (96%-98%) on room air. He was subsequently discharged in stable condition on a 2-week prednisone taper starting at 30 mg bid.
Thirteen days later, he was readmitted with a right frontoparietal cerebrovascular accident (CVA). He developed respiratory distress, which led to respiratory arrest, and was ventilated. He became hypotensive, lapsed into shock, and died a few days later (approximately one month after initial presentation).
The appropriate use of allopurinol—a second look
This case raised many questions for our inpatient team concerning not just AHS, but the appropriate use and dosing of allopurinol. Allopurinol is widely used for hyperuricemia and gout because it is effective for all causes of hyperuricemia and is inexpensive. Given that 3.9%12 of the general population has gout and that its prevalence has increased with rising rates of obesity, the importance of AHS is not abstract.
Revisiting initial treatment choices. Our patient was at risk for this syndrome due to his Chinese ancestry, recent onset of allopurinol therapy, concomitant use of triamterene/hydrochlorothiazide, and impaired renal function. Although his uric acid level was >10 mg/dL when treatment was started, his risk factors may have precluded initiation of allopurinol. Furthermore, the prescribed dose of allopurinol (300 mg) was too high for his baseline GFR; 100 mg daily would have been more appropriate. It could be argued that hydrochlorothiazide would not be an antihypertensive of choice due to its hyperuricemic effects. Switching the thiazide to a loop diuretic would offer no benefit, because loop diuretics also cause hyperuricemia. (More on which antihypertensive agent would have been appropriate in a bit.)
The role of AHS in the patient’s death is unclear. He was at high risk for stroke considering his age, comorbidities, and evidence of an old lacunar infarct. Myocardial infarctions have been reported as one cause of death in AHS, but we have found no reports of associated stroke. However, the temporal proximity of the CVA suggests a contributing effect of AHS. The adequacy of treatment is also brought into question. Early withdrawal of glucocorticoids can be associated with relapse of AHS; in retrospect, the prednisone dose may have been too low or the taper too short, or both.
Therapeutic alternatives to allopurinol were available. The most appropriate initial option for this patient likely was no pharmacologic intervention at all but a focus on weight loss and diet. The risk of gouty attacks in men increases as body mass index rises above normal (≥25 kg/m2) and decreases with weight loss. Lower calorie diets with decreased saturated fat, higher complex carbohydrates, and allowed proteins (low-fat dairy products) are more palatable and more effective than strict low-purine diets.
A urate-lowering antihypertensive may have been a better option—specifically, losartan rather than irbesartan and triamterene/hydrochlorothiazide.8,13 Losartan has uricosuric properties at the 50-mg dose.14 When compared in different studies with irbesartan, enalapril, and candesartan, losartan alone lowered serum urate levels. Increasing losartan to 100 mg could provide better hypertensive control but has not been found to lower urate levels more dramatically than the lower dose.13
Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been found to blunt the urate-elevating effects of thiazides. Therefore, if the patient’s blood pressure was not adequately controlled on losartan alone, the combination of losartan/hydrochlorothiazide would be a reasonable choice because minimal or no change in serum uric acid levels would be expected.15
Febuxostat, a nonpurine selective inhibitor of xanthine oxidase, is a potential alternative to allopurinol in patients with gout. It is a more potent urate-lowering agent than allopurinol and can be used without dosage reduction in mild (creatinine clearance [CrCl], 60-89 mL/min) to moderate (CrCl, 30-59 mL/ min) renal insufficiency. Febuxostat is metabolized primarily in the liver—in contrast to allopurinol, which is excreted by the kidneys—and may increase liver transaminase levels.10 Although febuxostat was not available at the time our patient developed AHS, it would not have been indicated in asymptomatic hyperuricemia.
This compelling case reminds us to carefully consider the indications and risk factors in using allopurinol, and to be aware of the rare but sometimes devastating consequences of this commonly used drug.
CORRESPONDENCE
Tahirah Tyrell, MD, Rochester General Medical Group, 1425 Portland Avenue, Rochester, NY 14621;
[email protected].
1. Lee HY, Ariyasinghe J, Thirumoorthy T. Allopurinol hypersensitivity syndrome: a preventable severe cutaneous adverse reaction? Singapore Med J. 2008;49:384-387.
2. Markel A. Allopurinol hypersensitivity and DRESS syndrome. Am J Med. 2008;121:e25.
3. Koike K, et al. Adverse reaction case reports. React Wkly. 2008 Sept 6;1218:5.
4. Mete N, Yilmaz F, et al. Adverse reaction case reports. React Wkly. 2004 June 26;1007:7.
5. Benito-León J, Porta-Etessam J. Guillain-Barré syndrome and allopurinol- induced hypersensitivity. Eur Neurol. 2001;45:186-187.
6. Makar-Ausperger KMA. Allopurinol/furosemide. Hypersensitivity syndrome: case report. Reactions Wkly. 2007 Oct 13;1173:5.
7. Singer JZ, Wallace SL. The allopurinol hypersensitivity syndrome. Unnecessary morbidity and mortality. Arthritis Rheum. 1986; 29: 82-87.
8. Becker M. Prevention of recurrent gout. UpToDate. April 10, 2013. Available at: http://www.uptodate.com/contents/prevention-ofrecurrent- gout?detectedLanguage=en&source=search_result&s earch=Prevention+of+recurrent+gout&selectedTitle=1%7E8&pr ovider=noProvider. Accessed August 1, 2013.
9. Ramasamy SN, Korb-Wells CS, Kannangara DR, et al. Allopurinol hypersensitivity: a systematic review of all published cases, 1950- 2012. Drug Saf. 2013;July 20. [Epub ahead of print].
10. Moreland LW. Febuxostat–treatment for hyperuricemia and gout? N Engl J Med. 2005;353:2505-2507.
11. Stamp LK, Taylor WJ, Jones PB, et al. Starting dose is a risk factor for allopurinol hypersensitivity syndrome: a proposed safe starting dose of allopurinol. Arthritis Rheum. 2012;64:2529-2536.
12. Zhu Y, Pandya BJ, Choi HK. Prevalence of gout and hyperuricemia in the US general population: the National Health and Nutrition Examination Survey 2007-2008. Arthritis Rheum. 2011;63: 3136-3141.
13. Würzner G, Gerster JC, Chiolero A, et al. Comparative effects of losartan and irbesartan on serum uric acid in hypertensive patients with hyperuricemia and gout. J Hypertens. 2001;19:1855-1860.
14. Terkeltaub RA. Clinical practice. gout. N Engl J Med. 2003;349:1647-1655.
15. Manolis AJ, Grossman E, Jelakovic B, et al. Effects of losartan and candesartan monotherapy and losartan/hydrochlorothiazide combination therapy in patients with mild to moderate hypertension. Losartan Trial Investigators. Clin Ther. 2000;22:1186-1203.
1. Lee HY, Ariyasinghe J, Thirumoorthy T. Allopurinol hypersensitivity syndrome: a preventable severe cutaneous adverse reaction? Singapore Med J. 2008;49:384-387.
2. Markel A. Allopurinol hypersensitivity and DRESS syndrome. Am J Med. 2008;121:e25.
3. Koike K, et al. Adverse reaction case reports. React Wkly. 2008 Sept 6;1218:5.
4. Mete N, Yilmaz F, et al. Adverse reaction case reports. React Wkly. 2004 June 26;1007:7.
5. Benito-León J, Porta-Etessam J. Guillain-Barré syndrome and allopurinol- induced hypersensitivity. Eur Neurol. 2001;45:186-187.
6. Makar-Ausperger KMA. Allopurinol/furosemide. Hypersensitivity syndrome: case report. Reactions Wkly. 2007 Oct 13;1173:5.
7. Singer JZ, Wallace SL. The allopurinol hypersensitivity syndrome. Unnecessary morbidity and mortality. Arthritis Rheum. 1986; 29: 82-87.
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