Pulmonary embolism (PE) and deep venous thrombosis (DVT), historically referred to together as venous thromboembolism (VTE), are common, treatable, sometimes fatal, and potentially preventable medical problems.[1] Such thromboses can both precipitate a hospitalization as well as complicate it (either during or soon after discharge). Preventing such thrombosis as a complication of medical care has become a national imperative. Landmark studies such as Prophylaxis in Medical Patients With Enoxaparin (MEDENOX)[2] and Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilized Patients Trial (PREVENT)[3] demonstrated both a high incidence of thrombosis in a hospitalized high‐risk medical population (15% and 5% in the 2 trials' placebo arms, respectively) as well as significant relative risk reduction through venous thromboembolism pharmacoprophylaxis (VTEP)63% and 45%, respectively. The Joint Commission,[4] the Society of Hospital Medicine,[5] and the American College of Chest Physicians[6, 7] have thus all strived to ensure the appropriate provision of VTEP in order to reduce the morbidity and mortality associated with thrombosis in hospitalized patients, including those on medical services.

Ideally, the global success of these efforts would be assessed by measuring the rate of hospital‐associated VTE (potentially including superficial venous thrombosis [SVT], which, like upper‐extremity deep venous thrombosis [UE‐DVT], is commonly a central venous catheter [CVC]‐associated, or peripherally inserted central catheter [PICC]‐associated, complication)thrombosis acquired and diagnosed during either the index hospitalization (hospital‐acquired, or HA‐VTE/SVT) or up to 30 days postdischarge. Unfortunately, postdischarge VTE/SVT is difficult to measure because patients developing it may not present to the original hospital, or at all (eg, if they do not seek care, are treated as outpatients, or, in the most extreme case, die at home). In this context, despite being far less comprehensive, HA‐VTE/SVT is a useful subset of hospital‐associated VTE/SVT, for several reasons. First, the Centers for Medicare & Medicaid Services (CMS) have mandated hospitals to qualify all medical diagnoses as present‐on‐admission (POA = Y) or not (POA = N) since 2008, such that all medical diagnoses coded POA = N can be considered hospital acquired.[8] Second, refinements made to the International Classification of Diseases, 9th Revision (ICD‐9) codes now allow differentiation of UE‐DVT and SVT from lower‐extremity (LE) DVT/PE, whereas the former were sometimes obscured by nonspecific coding.[9] Third, recent studies have shown that medical diagnoses administratively coded as HA‐VTE/SVT correlated well with HA‐VTE/SVT ascertained through chart review.[9, 10] Finally, previous work has estimated that approximately half of all hospital‐associated VTE are HA‐VTE and the other half are postdischarge VTE.[11] Thus, HA‐VTE, though comprising only approximately half of all hospital‐associated VTE, is often used as a surrogate for measuring the success of ongoing VTE prevention programs.[12]

Our study aimed to assess the incidence of HA‐VTE plus HA‐SVT in the era of mandatory POA coding and newer ICD‐9 codes for VTE.

METHODS

RESULTS

For the 18‐month period between October 1, 2009, and March 31, 2011, across 83 UHC hospitals, there were 2,525,068 cases. Among these, 12,847 (0.51%) had 1 HA‐VTE/SVT coded. As per the clinical importance hierarchy described above, 2449 (19.1%) cases had at least a PE coded; 3848 (30%) had at least a LE‐DVT (but not a PE) coded; 2893 (22.5%) had at least an UE‐DVT coded; 3248 (25.3%) had at least an SVT coded; 30 had at least a chronic VTE coded; and 379 had at least a VTE coded with no specified location. Of those with SVT, 192 (5.8%) were LE‐SVT codes, whereas the rest were SVT/thrombophlebitis of the upper extremities or not otherwise specified. There were 11,882 (92.5%) hospitalizations with a single HA‐VTE/SVT code and an additional 965 (7.5%) with multiple codes, for a total of 13,749 HA‐VTE/SVT events (see Supporting Information, Table S1, in the online version of this article for more specific data for the individual ICD‐9 codes used to specify HA‐VTE events).

Compared with those who did not develop any HA‐VTE/SVT, patients with HA‐PE/LE‐DVT were more likely to be Caucasian (65% vs 58%, P < 0.001) and were older (age 62 vs 48 years, P < 0.001) and sicker (79.9% vs 44.9% with a severe or extreme SOI, P < 0.001). They also were more likely to have cancer, have longer lengths of stay, be more likely to stay in the ICU, and die in the hospital (P < 0.001 for all comparisons; Table 1).

Among cases with a code for UE‐DVT (22.5% of all patients with HA‐VTE), 74% were noted to also have a code for a CVC, as did 60% of cases with a HA‐SVT of the antecubital, basilic, or cephalic veins (71% of SVT events; see Supporting Information, Table S1, in the online version of this article).

Of those with HA‐PE/LE‐DVT, 54.9% received pharmacologic prophylaxis on hospital day 1 or 2 (mostly with low‐molecular‐weight heparin or unfractionated heparin).

DISCUSSION

In this study of medical patients admitted to academic medical centers throughout the United States, we found that HA‐VTE/SVT was coded in approximately 0.51% of discharges, and the incidence of HA‐PE/LE‐DVT was 0.25%. Patients with a HA‐PE/LE‐DVT code were, in general, older and sicker than those who did not develop VTE. We further found that close to half of all HA‐VTE/SVT occurred in the upper extremity, with the majority of these occurring in patients who had CVCs. Finally, the majority of patients diagnosed with HA‐PE/LE‐DVT were started on VTEP on the first or second hospital day.

The overall incidence of HA‐VTE/SVT we discovered corresponds well to other studies, even those with disparate populations. A single‐institution study found a HA‐VTE/SVT incidence of approximately 0.6% among hospitalized patients on medical and nonmedical services.[12] The study by Barba found a rate of 0.93%,[18] whereas the study by Lederle found a rate of approximately 1%.[19] Spyropolous found an HA‐VTE incidence of 0.55%.[11] Rothberg found a lower rate of 0.25% in his risk‐stratification study, though in the pre‐POA and preupdated code era.[20] Our findings extend and provide context for, in a much larger population, the results of these prior studies, and represent the first national examination of HA‐VTE/SVT in the setting of numerous quality‐improvement and other efforts to reduce hospital‐associated VTE.

The incidence of HA‐VTE/SVT codes we observed likely underestimates the incidence of hospital‐associated VTE/SVT by a factor of approximately 4, for 2 reasons. First, although VTE/SVT codes with a POA flag set to No are truly hospital‐acquired events on chart review approximately 75% of the time, and thus overestimate HA‐VTE/SVT, 25% of POA = Yes codes are actually HA‐VTE/SVT events on chart review, and therefore lead to underestimation of HA‐VTE/SVT.[9] Because VTE/SVT codes with a POA flag set to Yes outnumber those flagged No by 3 or 4 to 1, events mis‐flagged Yes contribute a much greater number of undercounted HA‐VTE/SVT, elevating the actual HA‐VTE/SVT event rate by a factor of approximately 2. Second, HA‐VTE events do not include hospital‐associated VTE events that are diagnosed after the index hospitalization. In the Spyropolous study, 45% of hospital‐associated VTE events occurred after discharge, so translating HA‐VTE/SVT events to hospital‐associated VTE/SVT events would again involve multiplying by a factor of 2.[11] Thus, the overall incidence of hospital‐associated VTE/SVT events in our sample may have been approximately 2% (0.51% 4), and the overall incidence of hospital‐associated PE or LE‐DVT events may have been approximately 1%, though there may be significant variation around these estimates given that individual institutions were themselves quite variable in their POA flag accuracy in our study.[9] There is additionally the possibility that hospitals may have deliberately left some VTE/SVT uncoded, but in the absence of financial incentives to do so for anything other than postsurgical VTE, and in the presence of penalties from CMS for undercoding, we believe this to be unlikely, at least at present.

Despite these upward extrapolations, the estimated incidence of hospital‐associated VTE/SVT in our study may seem low compared with that reported in the MEDENOX[2] and PREVENT studies.[3] Much of this discrepancy vanishes on closer examination. In the large randomized trials, patients were uniformly and routinely assessed for LE‐DVT using vascular ultrasound; in contrast, in our population of hospitalizations patients may have only had diagnostic studies done for signs or symptoms. Clinically apparent hospital‐associated VTE is less common than all hospital‐associated VTE, as it was even in PREVENT,[3] and increased surveillance may even be partially driving increased hospital‐associated VTE/SVT at some hospitals.[21] Our findings suggest that success or failure in preventing administratively coded, clinically apparent HA LE‐VTE/PE should be judged, broadly, against numbers in the range established in our study (eg, 0.25%), not the 5% or 15% of chart‐abstracted, aggressively ascertained (and sometimes clinically silent) hospital‐associated VTE in the large randomized controlled trials. That is, 0.25% is not an achievement, but rather the average, expected value.

Almost 25% of the observed HA‐VTE/SVTs coded were UE‐DVT, with roughly 75% of these being likely related to central venous catheterization (including those peripherally inserted). An additional 1/5 were upper‐extremity SVT of the antecubital, cephalic, and basilic veins, with the majority of these (60%) also listed as catheter‐related. Such thrombosis is best prevented by decreased use of central catheters or perhaps by using smaller‐caliber catheters.[22] It is unclear if VTEP can prevent such clots, though in cancer patients at least one recent trial seems promising.[23]

We found that patients with a coded HA‐PE/LE‐DVT were remarkably different from those not developing HA‐VTE/SVT. Patients with HA‐PE or HA‐LE‐DVT were older, sicker, more likely to have cancer, significantly more likely to spend time in the ICU, and much more likely to die in the hospital; risk factors for HA‐VTE overlap significantly with risk factors for death in the hospital. A small majority (55%) of patients in the HA‐PE/LE‐DVT group had actually received VTEP on at least day 1 or 2 of hospitalization. It may be the case that the dose of VTEP was insufficient to suppress clot formation in these patients, or that HA‐PE/LE‐DVT in patients with this degree of comorbidity is difficult to prevent.

There are a number of limitations to our study. We analyzed administrative codes, which underestimate hospital‐associated VTE/SVT events as noted above. This was a descriptive study, cross‐sectional across each hospitalization, and we were unable to draw any causal inference for differences in HA‐VTE/SVT incidence that might exist between subpopulations. We estimated VTEP from medication usage in just the first 2 days of hospitalization; we could not assess mechanical prophylaxis in this dataset; and we did not have any VTEP data for the first 2 days of hospitalization on the patients who did not develop a HA‐VTE/SVT, which made it impossible to compare the 2 populations on this measure. For those who did not receive VTEP, we were unable to obtain data regarding possible contraindications to VTEP, such as ongoing gastrointestinal or intracerebral hemorrhage. Additionally, our data are based on academic hospitals only and may not generalize to nonacademic settings. Extrapolating from HA‐VTE/SVT to hospital‐associated VTE/SVT may not be possible due to heterogeneity of clotting events and perhaps variability in whether patients would return to the hospital for all of them (eg, superficial or UE VTE may not result in readmission). Finally, it is unclear whether a switch to ICD Tenth Revision (ICD‐10) codes will impact our measured baseline in the coming year. The strengths of our analysis included stratification by type of HA‐VTE/SVT and our ability to assess the incidence of HA‐VTE/SVT in a large national population, and the provision of a baseline for VTE incidenceeasily usable by any individual hospital, network, or researcher with access to administrative datagoing forward.

In conclusion, among patients hospitalized in academic medical centers, HA‐VTE/SVT was coded in approximately 0.51% of patients with a medical illness staying >2 days, with approximately half of the events due to HA‐PE/LE‐DVT. Patients who developed HA‐PE/LE‐DVT were more acutely ill than those who did not, and VTE developed despite 55% of these patients receiving VTEP on day 1 or 2. Hospitals can reasonably treat the 0.25% figure as the baseline around which to assess their own performance in preventing HA‐PE/LE‐DVT, and can measure their own performance using administrative data. Further research is needed to determine how best to achieve further reductions in HA‐VTE/SVT through risk stratification and/or through other interventions.

Pulmonary embolism (PE) and deep venous thrombosis (DVT), historically referred to together as venous thromboembolism (VTE), are common, treatable, sometimes fatal, and potentially preventable medical problems.[1] Such thromboses can both precipitate a hospitalization as well as complicate it (either during or soon after discharge). Preventing such thrombosis as a complication of medical care has become a national imperative. Landmark studies such as Prophylaxis in Medical Patients With Enoxaparin (MEDENOX)[2] and Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilized Patients Trial (PREVENT)[3] demonstrated both a high incidence of thrombosis in a hospitalized high‐risk medical population (15% and 5% in the 2 trials' placebo arms, respectively) as well as significant relative risk reduction through venous thromboembolism pharmacoprophylaxis (VTEP)63% and 45%, respectively. The Joint Commission,[4] the Society of Hospital Medicine,[5] and the American College of Chest Physicians[6, 7] have thus all strived to ensure the appropriate provision of VTEP in order to reduce the morbidity and mortality associated with thrombosis in hospitalized patients, including those on medical services.

Ideally, the global success of these efforts would be assessed by measuring the rate of hospital‐associated VTE (potentially including superficial venous thrombosis [SVT], which, like upper‐extremity deep venous thrombosis [UE‐DVT], is commonly a central venous catheter [CVC]‐associated, or peripherally inserted central catheter [PICC]‐associated, complication)thrombosis acquired and diagnosed during either the index hospitalization (hospital‐acquired, or HA‐VTE/SVT) or up to 30 days postdischarge. Unfortunately, postdischarge VTE/SVT is difficult to measure because patients developing it may not present to the original hospital, or at all (eg, if they do not seek care, are treated as outpatients, or, in the most extreme case, die at home). In this context, despite being far less comprehensive, HA‐VTE/SVT is a useful subset of hospital‐associated VTE/SVT, for several reasons. First, the Centers for Medicare & Medicaid Services (CMS) have mandated hospitals to qualify all medical diagnoses as present‐on‐admission (POA = Y) or not (POA = N) since 2008, such that all medical diagnoses coded POA = N can be considered hospital acquired.[8] Second, refinements made to the International Classification of Diseases, 9th Revision (ICD‐9) codes now allow differentiation of UE‐DVT and SVT from lower‐extremity (LE) DVT/PE, whereas the former were sometimes obscured by nonspecific coding.[9] Third, recent studies have shown that medical diagnoses administratively coded as HA‐VTE/SVT correlated well with HA‐VTE/SVT ascertained through chart review.[9, 10] Finally, previous work has estimated that approximately half of all hospital‐associated VTE are HA‐VTE and the other half are postdischarge VTE.[11] Thus, HA‐VTE, though comprising only approximately half of all hospital‐associated VTE, is often used as a surrogate for measuring the success of ongoing VTE prevention programs.[12]

Our study aimed to assess the incidence of HA‐VTE plus HA‐SVT in the era of mandatory POA coding and newer ICD‐9 codes for VTE.

METHODS

RESULTS

For the 18‐month period between October 1, 2009, and March 31, 2011, across 83 UHC hospitals, there were 2,525,068 cases. Among these, 12,847 (0.51%) had 1 HA‐VTE/SVT coded. As per the clinical importance hierarchy described above, 2449 (19.1%) cases had at least a PE coded; 3848 (30%) had at least a LE‐DVT (but not a PE) coded; 2893 (22.5%) had at least an UE‐DVT coded; 3248 (25.3%) had at least an SVT coded; 30 had at least a chronic VTE coded; and 379 had at least a VTE coded with no specified location. Of those with SVT, 192 (5.8%) were LE‐SVT codes, whereas the rest were SVT/thrombophlebitis of the upper extremities or not otherwise specified. There were 11,882 (92.5%) hospitalizations with a single HA‐VTE/SVT code and an additional 965 (7.5%) with multiple codes, for a total of 13,749 HA‐VTE/SVT events (see Supporting Information, Table S1, in the online version of this article for more specific data for the individual ICD‐9 codes used to specify HA‐VTE events).

Compared with those who did not develop any HA‐VTE/SVT, patients with HA‐PE/LE‐DVT were more likely to be Caucasian (65% vs 58%, P < 0.001) and were older (age 62 vs 48 years, P < 0.001) and sicker (79.9% vs 44.9% with a severe or extreme SOI, P < 0.001). They also were more likely to have cancer, have longer lengths of stay, be more likely to stay in the ICU, and die in the hospital (P < 0.001 for all comparisons; Table 1).

Among cases with a code for UE‐DVT (22.5% of all patients with HA‐VTE), 74% were noted to also have a code for a CVC, as did 60% of cases with a HA‐SVT of the antecubital, basilic, or cephalic veins (71% of SVT events; see Supporting Information, Table S1, in the online version of this article).

Of those with HA‐PE/LE‐DVT, 54.9% received pharmacologic prophylaxis on hospital day 1 or 2 (mostly with low‐molecular‐weight heparin or unfractionated heparin).

DISCUSSION

In this study of medical patients admitted to academic medical centers throughout the United States, we found that HA‐VTE/SVT was coded in approximately 0.51% of discharges, and the incidence of HA‐PE/LE‐DVT was 0.25%. Patients with a HA‐PE/LE‐DVT code were, in general, older and sicker than those who did not develop VTE. We further found that close to half of all HA‐VTE/SVT occurred in the upper extremity, with the majority of these occurring in patients who had CVCs. Finally, the majority of patients diagnosed with HA‐PE/LE‐DVT were started on VTEP on the first or second hospital day.

The overall incidence of HA‐VTE/SVT we discovered corresponds well to other studies, even those with disparate populations. A single‐institution study found a HA‐VTE/SVT incidence of approximately 0.6% among hospitalized patients on medical and nonmedical services.[12] The study by Barba found a rate of 0.93%,[18] whereas the study by Lederle found a rate of approximately 1%.[19] Spyropolous found an HA‐VTE incidence of 0.55%.[11] Rothberg found a lower rate of 0.25% in his risk‐stratification study, though in the pre‐POA and preupdated code era.[20] Our findings extend and provide context for, in a much larger population, the results of these prior studies, and represent the first national examination of HA‐VTE/SVT in the setting of numerous quality‐improvement and other efforts to reduce hospital‐associated VTE.

The incidence of HA‐VTE/SVT codes we observed likely underestimates the incidence of hospital‐associated VTE/SVT by a factor of approximately 4, for 2 reasons. First, although VTE/SVT codes with a POA flag set to No are truly hospital‐acquired events on chart review approximately 75% of the time, and thus overestimate HA‐VTE/SVT, 25% of POA = Yes codes are actually HA‐VTE/SVT events on chart review, and therefore lead to underestimation of HA‐VTE/SVT.[9] Because VTE/SVT codes with a POA flag set to Yes outnumber those flagged No by 3 or 4 to 1, events mis‐flagged Yes contribute a much greater number of undercounted HA‐VTE/SVT, elevating the actual HA‐VTE/SVT event rate by a factor of approximately 2. Second, HA‐VTE events do not include hospital‐associated VTE events that are diagnosed after the index hospitalization. In the Spyropolous study, 45% of hospital‐associated VTE events occurred after discharge, so translating HA‐VTE/SVT events to hospital‐associated VTE/SVT events would again involve multiplying by a factor of 2.[11] Thus, the overall incidence of hospital‐associated VTE/SVT events in our sample may have been approximately 2% (0.51% 4), and the overall incidence of hospital‐associated PE or LE‐DVT events may have been approximately 1%, though there may be significant variation around these estimates given that individual institutions were themselves quite variable in their POA flag accuracy in our study.[9] There is additionally the possibility that hospitals may have deliberately left some VTE/SVT uncoded, but in the absence of financial incentives to do so for anything other than postsurgical VTE, and in the presence of penalties from CMS for undercoding, we believe this to be unlikely, at least at present.

Despite these upward extrapolations, the estimated incidence of hospital‐associated VTE/SVT in our study may seem low compared with that reported in the MEDENOX[2] and PREVENT studies.[3] Much of this discrepancy vanishes on closer examination. In the large randomized trials, patients were uniformly and routinely assessed for LE‐DVT using vascular ultrasound; in contrast, in our population of hospitalizations patients may have only had diagnostic studies done for signs or symptoms. Clinically apparent hospital‐associated VTE is less common than all hospital‐associated VTE, as it was even in PREVENT,[3] and increased surveillance may even be partially driving increased hospital‐associated VTE/SVT at some hospitals.[21] Our findings suggest that success or failure in preventing administratively coded, clinically apparent HA LE‐VTE/PE should be judged, broadly, against numbers in the range established in our study (eg, 0.25%), not the 5% or 15% of chart‐abstracted, aggressively ascertained (and sometimes clinically silent) hospital‐associated VTE in the large randomized controlled trials. That is, 0.25% is not an achievement, but rather the average, expected value.

Almost 25% of the observed HA‐VTE/SVTs coded were UE‐DVT, with roughly 75% of these being likely related to central venous catheterization (including those peripherally inserted). An additional 1/5 were upper‐extremity SVT of the antecubital, cephalic, and basilic veins, with the majority of these (60%) also listed as catheter‐related. Such thrombosis is best prevented by decreased use of central catheters or perhaps by using smaller‐caliber catheters.[22] It is unclear if VTEP can prevent such clots, though in cancer patients at least one recent trial seems promising.[23]

We found that patients with a coded HA‐PE/LE‐DVT were remarkably different from those not developing HA‐VTE/SVT. Patients with HA‐PE or HA‐LE‐DVT were older, sicker, more likely to have cancer, significantly more likely to spend time in the ICU, and much more likely to die in the hospital; risk factors for HA‐VTE overlap significantly with risk factors for death in the hospital. A small majority (55%) of patients in the HA‐PE/LE‐DVT group had actually received VTEP on at least day 1 or 2 of hospitalization. It may be the case that the dose of VTEP was insufficient to suppress clot formation in these patients, or that HA‐PE/LE‐DVT in patients with this degree of comorbidity is difficult to prevent.

There are a number of limitations to our study. We analyzed administrative codes, which underestimate hospital‐associated VTE/SVT events as noted above. This was a descriptive study, cross‐sectional across each hospitalization, and we were unable to draw any causal inference for differences in HA‐VTE/SVT incidence that might exist between subpopulations. We estimated VTEP from medication usage in just the first 2 days of hospitalization; we could not assess mechanical prophylaxis in this dataset; and we did not have any VTEP data for the first 2 days of hospitalization on the patients who did not develop a HA‐VTE/SVT, which made it impossible to compare the 2 populations on this measure. For those who did not receive VTEP, we were unable to obtain data regarding possible contraindications to VTEP, such as ongoing gastrointestinal or intracerebral hemorrhage. Additionally, our data are based on academic hospitals only and may not generalize to nonacademic settings. Extrapolating from HA‐VTE/SVT to hospital‐associated VTE/SVT may not be possible due to heterogeneity of clotting events and perhaps variability in whether patients would return to the hospital for all of them (eg, superficial or UE VTE may not result in readmission). Finally, it is unclear whether a switch to ICD Tenth Revision (ICD‐10) codes will impact our measured baseline in the coming year. The strengths of our analysis included stratification by type of HA‐VTE/SVT and our ability to assess the incidence of HA‐VTE/SVT in a large national population, and the provision of a baseline for VTE incidenceeasily usable by any individual hospital, network, or researcher with access to administrative datagoing forward.

In conclusion, among patients hospitalized in academic medical centers, HA‐VTE/SVT was coded in approximately 0.51% of patients with a medical illness staying >2 days, with approximately half of the events due to HA‐PE/LE‐DVT. Patients who developed HA‐PE/LE‐DVT were more acutely ill than those who did not, and VTE developed despite 55% of these patients receiving VTEP on day 1 or 2. Hospitals can reasonably treat the 0.25% figure as the baseline around which to assess their own performance in preventing HA‐PE/LE‐DVT, and can measure their own performance using administrative data. Further research is needed to determine how best to achieve further reductions in HA‐VTE/SVT through risk stratification and/or through other interventions.

Pulmonary embolism (PE) and deep venous thrombosis (DVT), historically referred to together as venous thromboembolism (VTE), are common, treatable, sometimes fatal, and potentially preventable medical problems.[1] Such thromboses can both precipitate a hospitalization as well as complicate it (either during or soon after discharge). Preventing such thrombosis as a complication of medical care has become a national imperative. Landmark studies such as Prophylaxis in Medical Patients With Enoxaparin (MEDENOX)[2] and Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilized Patients Trial (PREVENT)[3] demonstrated both a high incidence of thrombosis in a hospitalized high‐risk medical population (15% and 5% in the 2 trials' placebo arms, respectively) as well as significant relative risk reduction through venous thromboembolism pharmacoprophylaxis (VTEP)63% and 45%, respectively. The Joint Commission,[4] the Society of Hospital Medicine,[5] and the American College of Chest Physicians[6, 7] have thus all strived to ensure the appropriate provision of VTEP in order to reduce the morbidity and mortality associated with thrombosis in hospitalized patients, including those on medical services.

Ideally, the global success of these efforts would be assessed by measuring the rate of hospital‐associated VTE (potentially including superficial venous thrombosis [SVT], which, like upper‐extremity deep venous thrombosis [UE‐DVT], is commonly a central venous catheter [CVC]‐associated, or peripherally inserted central catheter [PICC]‐associated, complication)thrombosis acquired and diagnosed during either the index hospitalization (hospital‐acquired, or HA‐VTE/SVT) or up to 30 days postdischarge. Unfortunately, postdischarge VTE/SVT is difficult to measure because patients developing it may not present to the original hospital, or at all (eg, if they do not seek care, are treated as outpatients, or, in the most extreme case, die at home). In this context, despite being far less comprehensive, HA‐VTE/SVT is a useful subset of hospital‐associated VTE/SVT, for several reasons. First, the Centers for Medicare & Medicaid Services (CMS) have mandated hospitals to qualify all medical diagnoses as present‐on‐admission (POA = Y) or not (POA = N) since 2008, such that all medical diagnoses coded POA = N can be considered hospital acquired.[8] Second, refinements made to the International Classification of Diseases, 9th Revision (ICD‐9) codes now allow differentiation of UE‐DVT and SVT from lower‐extremity (LE) DVT/PE, whereas the former were sometimes obscured by nonspecific coding.[9] Third, recent studies have shown that medical diagnoses administratively coded as HA‐VTE/SVT correlated well with HA‐VTE/SVT ascertained through chart review.[9, 10] Finally, previous work has estimated that approximately half of all hospital‐associated VTE are HA‐VTE and the other half are postdischarge VTE.[11] Thus, HA‐VTE, though comprising only approximately half of all hospital‐associated VTE, is often used as a surrogate for measuring the success of ongoing VTE prevention programs.[12]

Our study aimed to assess the incidence of HA‐VTE plus HA‐SVT in the era of mandatory POA coding and newer ICD‐9 codes for VTE.

METHODS

RESULTS

For the 18‐month period between October 1, 2009, and March 31, 2011, across 83 UHC hospitals, there were 2,525,068 cases. Among these, 12,847 (0.51%) had 1 HA‐VTE/SVT coded. As per the clinical importance hierarchy described above, 2449 (19.1%) cases had at least a PE coded; 3848 (30%) had at least a LE‐DVT (but not a PE) coded; 2893 (22.5%) had at least an UE‐DVT coded; 3248 (25.3%) had at least an SVT coded; 30 had at least a chronic VTE coded; and 379 had at least a VTE coded with no specified location. Of those with SVT, 192 (5.8%) were LE‐SVT codes, whereas the rest were SVT/thrombophlebitis of the upper extremities or not otherwise specified. There were 11,882 (92.5%) hospitalizations with a single HA‐VTE/SVT code and an additional 965 (7.5%) with multiple codes, for a total of 13,749 HA‐VTE/SVT events (see Supporting Information, Table S1, in the online version of this article for more specific data for the individual ICD‐9 codes used to specify HA‐VTE events).

Compared with those who did not develop any HA‐VTE/SVT, patients with HA‐PE/LE‐DVT were more likely to be Caucasian (65% vs 58%, P < 0.001) and were older (age 62 vs 48 years, P < 0.001) and sicker (79.9% vs 44.9% with a severe or extreme SOI, P < 0.001). They also were more likely to have cancer, have longer lengths of stay, be more likely to stay in the ICU, and die in the hospital (P < 0.001 for all comparisons; Table 1).

Among cases with a code for UE‐DVT (22.5% of all patients with HA‐VTE), 74% were noted to also have a code for a CVC, as did 60% of cases with a HA‐SVT of the antecubital, basilic, or cephalic veins (71% of SVT events; see Supporting Information, Table S1, in the online version of this article).

Of those with HA‐PE/LE‐DVT, 54.9% received pharmacologic prophylaxis on hospital day 1 or 2 (mostly with low‐molecular‐weight heparin or unfractionated heparin).

DISCUSSION

In this study of medical patients admitted to academic medical centers throughout the United States, we found that HA‐VTE/SVT was coded in approximately 0.51% of discharges, and the incidence of HA‐PE/LE‐DVT was 0.25%. Patients with a HA‐PE/LE‐DVT code were, in general, older and sicker than those who did not develop VTE. We further found that close to half of all HA‐VTE/SVT occurred in the upper extremity, with the majority of these occurring in patients who had CVCs. Finally, the majority of patients diagnosed with HA‐PE/LE‐DVT were started on VTEP on the first or second hospital day.

The overall incidence of HA‐VTE/SVT we discovered corresponds well to other studies, even those with disparate populations. A single‐institution study found a HA‐VTE/SVT incidence of approximately 0.6% among hospitalized patients on medical and nonmedical services.[12] The study by Barba found a rate of 0.93%,[18] whereas the study by Lederle found a rate of approximately 1%.[19] Spyropolous found an HA‐VTE incidence of 0.55%.[11] Rothberg found a lower rate of 0.25% in his risk‐stratification study, though in the pre‐POA and preupdated code era.[20] Our findings extend and provide context for, in a much larger population, the results of these prior studies, and represent the first national examination of HA‐VTE/SVT in the setting of numerous quality‐improvement and other efforts to reduce hospital‐associated VTE.

The incidence of HA‐VTE/SVT codes we observed likely underestimates the incidence of hospital‐associated VTE/SVT by a factor of approximately 4, for 2 reasons. First, although VTE/SVT codes with a POA flag set to No are truly hospital‐acquired events on chart review approximately 75% of the time, and thus overestimate HA‐VTE/SVT, 25% of POA = Yes codes are actually HA‐VTE/SVT events on chart review, and therefore lead to underestimation of HA‐VTE/SVT.[9] Because VTE/SVT codes with a POA flag set to Yes outnumber those flagged No by 3 or 4 to 1, events mis‐flagged Yes contribute a much greater number of undercounted HA‐VTE/SVT, elevating the actual HA‐VTE/SVT event rate by a factor of approximately 2. Second, HA‐VTE events do not include hospital‐associated VTE events that are diagnosed after the index hospitalization. In the Spyropolous study, 45% of hospital‐associated VTE events occurred after discharge, so translating HA‐VTE/SVT events to hospital‐associated VTE/SVT events would again involve multiplying by a factor of 2.[11] Thus, the overall incidence of hospital‐associated VTE/SVT events in our sample may have been approximately 2% (0.51% 4), and the overall incidence of hospital‐associated PE or LE‐DVT events may have been approximately 1%, though there may be significant variation around these estimates given that individual institutions were themselves quite variable in their POA flag accuracy in our study.[9] There is additionally the possibility that hospitals may have deliberately left some VTE/SVT uncoded, but in the absence of financial incentives to do so for anything other than postsurgical VTE, and in the presence of penalties from CMS for undercoding, we believe this to be unlikely, at least at present.

Despite these upward extrapolations, the estimated incidence of hospital‐associated VTE/SVT in our study may seem low compared with that reported in the MEDENOX[2] and PREVENT studies.[3] Much of this discrepancy vanishes on closer examination. In the large randomized trials, patients were uniformly and routinely assessed for LE‐DVT using vascular ultrasound; in contrast, in our population of hospitalizations patients may have only had diagnostic studies done for signs or symptoms. Clinically apparent hospital‐associated VTE is less common than all hospital‐associated VTE, as it was even in PREVENT,[3] and increased surveillance may even be partially driving increased hospital‐associated VTE/SVT at some hospitals.[21] Our findings suggest that success or failure in preventing administratively coded, clinically apparent HA LE‐VTE/PE should be judged, broadly, against numbers in the range established in our study (eg, 0.25%), not the 5% or 15% of chart‐abstracted, aggressively ascertained (and sometimes clinically silent) hospital‐associated VTE in the large randomized controlled trials. That is, 0.25% is not an achievement, but rather the average, expected value.

Almost 25% of the observed HA‐VTE/SVTs coded were UE‐DVT, with roughly 75% of these being likely related to central venous catheterization (including those peripherally inserted). An additional 1/5 were upper‐extremity SVT of the antecubital, cephalic, and basilic veins, with the majority of these (60%) also listed as catheter‐related. Such thrombosis is best prevented by decreased use of central catheters or perhaps by using smaller‐caliber catheters.[22] It is unclear if VTEP can prevent such clots, though in cancer patients at least one recent trial seems promising.[23]

We found that patients with a coded HA‐PE/LE‐DVT were remarkably different from those not developing HA‐VTE/SVT. Patients with HA‐PE or HA‐LE‐DVT were older, sicker, more likely to have cancer, significantly more likely to spend time in the ICU, and much more likely to die in the hospital; risk factors for HA‐VTE overlap significantly with risk factors for death in the hospital. A small majority (55%) of patients in the HA‐PE/LE‐DVT group had actually received VTEP on at least day 1 or 2 of hospitalization. It may be the case that the dose of VTEP was insufficient to suppress clot formation in these patients, or that HA‐PE/LE‐DVT in patients with this degree of comorbidity is difficult to prevent.

There are a number of limitations to our study. We analyzed administrative codes, which underestimate hospital‐associated VTE/SVT events as noted above. This was a descriptive study, cross‐sectional across each hospitalization, and we were unable to draw any causal inference for differences in HA‐VTE/SVT incidence that might exist between subpopulations. We estimated VTEP from medication usage in just the first 2 days of hospitalization; we could not assess mechanical prophylaxis in this dataset; and we did not have any VTEP data for the first 2 days of hospitalization on the patients who did not develop a HA‐VTE/SVT, which made it impossible to compare the 2 populations on this measure. For those who did not receive VTEP, we were unable to obtain data regarding possible contraindications to VTEP, such as ongoing gastrointestinal or intracerebral hemorrhage. Additionally, our data are based on academic hospitals only and may not generalize to nonacademic settings. Extrapolating from HA‐VTE/SVT to hospital‐associated VTE/SVT may not be possible due to heterogeneity of clotting events and perhaps variability in whether patients would return to the hospital for all of them (eg, superficial or UE VTE may not result in readmission). Finally, it is unclear whether a switch to ICD Tenth Revision (ICD‐10) codes will impact our measured baseline in the coming year. The strengths of our analysis included stratification by type of HA‐VTE/SVT and our ability to assess the incidence of HA‐VTE/SVT in a large national population, and the provision of a baseline for VTE incidenceeasily usable by any individual hospital, network, or researcher with access to administrative datagoing forward.

In conclusion, among patients hospitalized in academic medical centers, HA‐VTE/SVT was coded in approximately 0.51% of patients with a medical illness staying >2 days, with approximately half of the events due to HA‐PE/LE‐DVT. Patients who developed HA‐PE/LE‐DVT were more acutely ill than those who did not, and VTE developed despite 55% of these patients receiving VTEP on day 1 or 2. Hospitals can reasonably treat the 0.25% figure as the baseline around which to assess their own performance in preventing HA‐PE/LE‐DVT, and can measure their own performance using administrative data. Further research is needed to determine how best to achieve further reductions in HA‐VTE/SVT through risk stratification and/or through other interventions.

Reducing hospital admissions within 30 days of inpatient discharge is the focus of numerous policies, incentives, and payment models, led by the Centers for Medicare & Medicaid Services.[1] Accordingly, care‐transition programs have been developed and are found to be effective in reducing hospital readmissions.[2, 3] Interestingly, emergency department (ED) visits have not been included in this definition of readmission, no programs have focused specifically on reducing ED visits,[4] and some have even increased ED visits.[5]

The prevalence and costs associated with ED care within 30 days of hospital discharge are not insignificant. Up to 24% of discharged patients present to the ED within 30 days, among whom only 50% are readmitted.[6] ED care alone accounts for nearly 40% of all costs in the acute postdischarge period.[7] This is in addition to the costs associated with readmissions from the ED, which are the result of disposition decisions made by ED clinicians.

To begin to build effective care‐transition programs to reduce ED visits after inpatient discharge, greater understanding is needed on what factors influence the utilization of the ED and what potential interventions could have prevented them. Studies from inpatient populations have been successful in eliciting these factors through stakeholder interviews.[8, 9, 10] In fact, the American College of Physicians and Society of Hospital Medicine emphasize involvement of the patient and family members in plans of care.[11] No prior studies have used stakeholders to inform care‐transition models for patients who return to the ED within 30 days of inpatient discharge.

Therefore, the primary objective of this study was to collect various stakeholder perspectives to improve the understanding of factors associated with ED visits within 30 days of hospital discharge and identify potentially useful interventions to prevent them. We hypothesized that there would be significant discordances between patients, their caregivers, and emergency physicians. Findings from this study could inform an expanded framework for understanding the complexity of care needs after hospital discharge and suggest interventions to improve health outcomes and to reduce healthcare costs.

METHODS

RESULTS

DISCUSSION

Several findings from this study can improve the understanding of what factors influence the utilization of the ED soon after inpatient discharge and what interventions could potentially prevent them. Consistent with our hypothesis, there are significant discordances between patients, their caregivers, and emergency physicians. Additionally, emergency physicians and caregivers were able to identify factors and potential opportunities for prevention a significant, albeit variable, amount of time the patients did not. Perhaps not surprisingly, we found that across stakeholders, the majority of ED visits are perceived as related to issues from the prior hospitalization or progression of chronic disease or medical condition. Of some concern, we found that less than half of patients, physicians, and caregivers could identify an intervention to potentially prevent the ED visit.

The large discordances between patients' and physicians' perceptions in our study were similar to those found in prior studies from primary care.[13, 14, 15] No prior study has examined discordances in emergency care or regarding perceptions about care‐transition difficulties. Feigenbaum et al.[10] interviewed patients, caregivers, and physicians to create composite definitions of potentially preventable readmissions. They did not, however, look at how these perceptions differ or describe the relative contribution of individual stakeholders to overall definitions. The discordances between patient and emergency physician perceptions may be due to a couple of potential causes. First, emergency physicians may have greater access to medical history data than patients, allowing them to develop more objective assessments. This is supported by our finding that physicians identified factors when patients did not. Second, patients may understand certain care‐transition difficulties that physicians do not elicit from history taking. This may be especially apparent in the emergency setting, where physicians are time limited and do not have established care relationships with patients.

The moderate agreement between patient and caregiver perceptions are similar to a couple of studies examining perceived quality of life among patients.[16, 17] These discordances can be due to a couple of potential causes. First, caregivers may witness deficits or transition difficulties that the patient may not. This may be particularly true for caregivers who are providing substantial support in managing the patient's healthcare or for patients with cognitive impairment. Second, caregivers may not know the patient history well enough to know what specific issues affect the patient. This would be likely when caregivers do not live with patients or serve a central role in caregiving.

The overwhelming perception that the majority of ED visits are related to issues from the prior hospitalization or progression of chronic disease or medical condition suggests that, by and large, acute care needs soon after hospital discharges are not new unrelated medical issues, and thus theoretically could be predicted and prevented. This is consistent with prior prediction models showing that chronic medical comorbidities have strong associations with hospital readmission.[18, 19] It also supports probing care issues with patients prior to hospital discharge.[20]

The finding that less than half of patients, physicians, or caregivers could identify an intervention to potentially prevent the ED visit echoes prior research, indicating that only a minority of readmissions may be truly preventable,[21] and suggests that there may not be obvious needs that can be addressed to prevent acute care visits. An alternative interpretation is that the healthcare system does not currently have a suitable alternative to meet the perceived needs of patients. Despite this, patients occasionally perceived that better discharge instructions, review of medications, and sooner follow‐up appointments with a primary care doctor could have potentially prevented their ED visit. This is consistent with numerous prior studies and supports better transition‐of‐care programs.

Our study had a small sample size, which results in wide confidence intervals on all point estimates of percentages, limiting the precision of our findings. No medical charts were reviewed to determine the medical reasons for the index admission, the prior course of care, or subsequent hospital course after emergency care, limiting our ability to link perceptions with actual past hospital experiences or compare differences in perceptions by subsequent readmission. Another limitation is a lack of generalizability of our findings to other patients, hospitals, or regions. Our patient population was largely white and English speaking only for participation in this study. Also, our hospital ED admits an average of 48% of patients, which is higher than most hospitals. We enrolled a convenience sample as opposed to a consecutive sample of patients due to limitations in research associate staffing, potentially biasing our sample. We attempted to minimize this bias by scheduling shifts across days and time periods. We did not systematically collect the number of patients or caregivers who refused participation, but believe that it was less than 5% of those approached. Other limitations include possible reporting biases associated with in‐person interviews, which we attempted to minimize by conducting all surveys in private.

SUMMARY

Identifying needs in patients who utilize the ED soon after being discharged from inpatient care is essential for planning appropriate care‐transition interventions. Our findings suggest that multiple stakeholders may be necessary to fully elicit targets for effective care‐transition programs.

Reducing hospital admissions within 30 days of inpatient discharge is the focus of numerous policies, incentives, and payment models, led by the Centers for Medicare & Medicaid Services.[1] Accordingly, care‐transition programs have been developed and are found to be effective in reducing hospital readmissions.[2, 3] Interestingly, emergency department (ED) visits have not been included in this definition of readmission, no programs have focused specifically on reducing ED visits,[4] and some have even increased ED visits.[5]

The prevalence and costs associated with ED care within 30 days of hospital discharge are not insignificant. Up to 24% of discharged patients present to the ED within 30 days, among whom only 50% are readmitted.[6] ED care alone accounts for nearly 40% of all costs in the acute postdischarge period.[7] This is in addition to the costs associated with readmissions from the ED, which are the result of disposition decisions made by ED clinicians.

To begin to build effective care‐transition programs to reduce ED visits after inpatient discharge, greater understanding is needed on what factors influence the utilization of the ED and what potential interventions could have prevented them. Studies from inpatient populations have been successful in eliciting these factors through stakeholder interviews.[8, 9, 10] In fact, the American College of Physicians and Society of Hospital Medicine emphasize involvement of the patient and family members in plans of care.[11] No prior studies have used stakeholders to inform care‐transition models for patients who return to the ED within 30 days of inpatient discharge.

Therefore, the primary objective of this study was to collect various stakeholder perspectives to improve the understanding of factors associated with ED visits within 30 days of hospital discharge and identify potentially useful interventions to prevent them. We hypothesized that there would be significant discordances between patients, their caregivers, and emergency physicians. Findings from this study could inform an expanded framework for understanding the complexity of care needs after hospital discharge and suggest interventions to improve health outcomes and to reduce healthcare costs.

METHODS

RESULTS

DISCUSSION

Several findings from this study can improve the understanding of what factors influence the utilization of the ED soon after inpatient discharge and what interventions could potentially prevent them. Consistent with our hypothesis, there are significant discordances between patients, their caregivers, and emergency physicians. Additionally, emergency physicians and caregivers were able to identify factors and potential opportunities for prevention a significant, albeit variable, amount of time the patients did not. Perhaps not surprisingly, we found that across stakeholders, the majority of ED visits are perceived as related to issues from the prior hospitalization or progression of chronic disease or medical condition. Of some concern, we found that less than half of patients, physicians, and caregivers could identify an intervention to potentially prevent the ED visit.

The large discordances between patients' and physicians' perceptions in our study were similar to those found in prior studies from primary care.[13, 14, 15] No prior study has examined discordances in emergency care or regarding perceptions about care‐transition difficulties. Feigenbaum et al.[10] interviewed patients, caregivers, and physicians to create composite definitions of potentially preventable readmissions. They did not, however, look at how these perceptions differ or describe the relative contribution of individual stakeholders to overall definitions. The discordances between patient and emergency physician perceptions may be due to a couple of potential causes. First, emergency physicians may have greater access to medical history data than patients, allowing them to develop more objective assessments. This is supported by our finding that physicians identified factors when patients did not. Second, patients may understand certain care‐transition difficulties that physicians do not elicit from history taking. This may be especially apparent in the emergency setting, where physicians are time limited and do not have established care relationships with patients.

The moderate agreement between patient and caregiver perceptions are similar to a couple of studies examining perceived quality of life among patients.[16, 17] These discordances can be due to a couple of potential causes. First, caregivers may witness deficits or transition difficulties that the patient may not. This may be particularly true for caregivers who are providing substantial support in managing the patient's healthcare or for patients with cognitive impairment. Second, caregivers may not know the patient history well enough to know what specific issues affect the patient. This would be likely when caregivers do not live with patients or serve a central role in caregiving.

The overwhelming perception that the majority of ED visits are related to issues from the prior hospitalization or progression of chronic disease or medical condition suggests that, by and large, acute care needs soon after hospital discharges are not new unrelated medical issues, and thus theoretically could be predicted and prevented. This is consistent with prior prediction models showing that chronic medical comorbidities have strong associations with hospital readmission.[18, 19] It also supports probing care issues with patients prior to hospital discharge.[20]

The finding that less than half of patients, physicians, or caregivers could identify an intervention to potentially prevent the ED visit echoes prior research, indicating that only a minority of readmissions may be truly preventable,[21] and suggests that there may not be obvious needs that can be addressed to prevent acute care visits. An alternative interpretation is that the healthcare system does not currently have a suitable alternative to meet the perceived needs of patients. Despite this, patients occasionally perceived that better discharge instructions, review of medications, and sooner follow‐up appointments with a primary care doctor could have potentially prevented their ED visit. This is consistent with numerous prior studies and supports better transition‐of‐care programs.

Our study had a small sample size, which results in wide confidence intervals on all point estimates of percentages, limiting the precision of our findings. No medical charts were reviewed to determine the medical reasons for the index admission, the prior course of care, or subsequent hospital course after emergency care, limiting our ability to link perceptions with actual past hospital experiences or compare differences in perceptions by subsequent readmission. Another limitation is a lack of generalizability of our findings to other patients, hospitals, or regions. Our patient population was largely white and English speaking only for participation in this study. Also, our hospital ED admits an average of 48% of patients, which is higher than most hospitals. We enrolled a convenience sample as opposed to a consecutive sample of patients due to limitations in research associate staffing, potentially biasing our sample. We attempted to minimize this bias by scheduling shifts across days and time periods. We did not systematically collect the number of patients or caregivers who refused participation, but believe that it was less than 5% of those approached. Other limitations include possible reporting biases associated with in‐person interviews, which we attempted to minimize by conducting all surveys in private.

SUMMARY

Identifying needs in patients who utilize the ED soon after being discharged from inpatient care is essential for planning appropriate care‐transition interventions. Our findings suggest that multiple stakeholders may be necessary to fully elicit targets for effective care‐transition programs.

Reducing hospital admissions within 30 days of inpatient discharge is the focus of numerous policies, incentives, and payment models, led by the Centers for Medicare & Medicaid Services.[1] Accordingly, care‐transition programs have been developed and are found to be effective in reducing hospital readmissions.[2, 3] Interestingly, emergency department (ED) visits have not been included in this definition of readmission, no programs have focused specifically on reducing ED visits,[4] and some have even increased ED visits.[5]

The prevalence and costs associated with ED care within 30 days of hospital discharge are not insignificant. Up to 24% of discharged patients present to the ED within 30 days, among whom only 50% are readmitted.[6] ED care alone accounts for nearly 40% of all costs in the acute postdischarge period.[7] This is in addition to the costs associated with readmissions from the ED, which are the result of disposition decisions made by ED clinicians.

To begin to build effective care‐transition programs to reduce ED visits after inpatient discharge, greater understanding is needed on what factors influence the utilization of the ED and what potential interventions could have prevented them. Studies from inpatient populations have been successful in eliciting these factors through stakeholder interviews.[8, 9, 10] In fact, the American College of Physicians and Society of Hospital Medicine emphasize involvement of the patient and family members in plans of care.[11] No prior studies have used stakeholders to inform care‐transition models for patients who return to the ED within 30 days of inpatient discharge.

Therefore, the primary objective of this study was to collect various stakeholder perspectives to improve the understanding of factors associated with ED visits within 30 days of hospital discharge and identify potentially useful interventions to prevent them. We hypothesized that there would be significant discordances between patients, their caregivers, and emergency physicians. Findings from this study could inform an expanded framework for understanding the complexity of care needs after hospital discharge and suggest interventions to improve health outcomes and to reduce healthcare costs.

METHODS

RESULTS

DISCUSSION

Several findings from this study can improve the understanding of what factors influence the utilization of the ED soon after inpatient discharge and what interventions could potentially prevent them. Consistent with our hypothesis, there are significant discordances between patients, their caregivers, and emergency physicians. Additionally, emergency physicians and caregivers were able to identify factors and potential opportunities for prevention a significant, albeit variable, amount of time the patients did not. Perhaps not surprisingly, we found that across stakeholders, the majority of ED visits are perceived as related to issues from the prior hospitalization or progression of chronic disease or medical condition. Of some concern, we found that less than half of patients, physicians, and caregivers could identify an intervention to potentially prevent the ED visit.

The large discordances between patients' and physicians' perceptions in our study were similar to those found in prior studies from primary care.[13, 14, 15] No prior study has examined discordances in emergency care or regarding perceptions about care‐transition difficulties. Feigenbaum et al.[10] interviewed patients, caregivers, and physicians to create composite definitions of potentially preventable readmissions. They did not, however, look at how these perceptions differ or describe the relative contribution of individual stakeholders to overall definitions. The discordances between patient and emergency physician perceptions may be due to a couple of potential causes. First, emergency physicians may have greater access to medical history data than patients, allowing them to develop more objective assessments. This is supported by our finding that physicians identified factors when patients did not. Second, patients may understand certain care‐transition difficulties that physicians do not elicit from history taking. This may be especially apparent in the emergency setting, where physicians are time limited and do not have established care relationships with patients.

The moderate agreement between patient and caregiver perceptions are similar to a couple of studies examining perceived quality of life among patients.[16, 17] These discordances can be due to a couple of potential causes. First, caregivers may witness deficits or transition difficulties that the patient may not. This may be particularly true for caregivers who are providing substantial support in managing the patient's healthcare or for patients with cognitive impairment. Second, caregivers may not know the patient history well enough to know what specific issues affect the patient. This would be likely when caregivers do not live with patients or serve a central role in caregiving.

The overwhelming perception that the majority of ED visits are related to issues from the prior hospitalization or progression of chronic disease or medical condition suggests that, by and large, acute care needs soon after hospital discharges are not new unrelated medical issues, and thus theoretically could be predicted and prevented. This is consistent with prior prediction models showing that chronic medical comorbidities have strong associations with hospital readmission.[18, 19] It also supports probing care issues with patients prior to hospital discharge.[20]

The finding that less than half of patients, physicians, or caregivers could identify an intervention to potentially prevent the ED visit echoes prior research, indicating that only a minority of readmissions may be truly preventable,[21] and suggests that there may not be obvious needs that can be addressed to prevent acute care visits. An alternative interpretation is that the healthcare system does not currently have a suitable alternative to meet the perceived needs of patients. Despite this, patients occasionally perceived that better discharge instructions, review of medications, and sooner follow‐up appointments with a primary care doctor could have potentially prevented their ED visit. This is consistent with numerous prior studies and supports better transition‐of‐care programs.

Our study had a small sample size, which results in wide confidence intervals on all point estimates of percentages, limiting the precision of our findings. No medical charts were reviewed to determine the medical reasons for the index admission, the prior course of care, or subsequent hospital course after emergency care, limiting our ability to link perceptions with actual past hospital experiences or compare differences in perceptions by subsequent readmission. Another limitation is a lack of generalizability of our findings to other patients, hospitals, or regions. Our patient population was largely white and English speaking only for participation in this study. Also, our hospital ED admits an average of 48% of patients, which is higher than most hospitals. We enrolled a convenience sample as opposed to a consecutive sample of patients due to limitations in research associate staffing, potentially biasing our sample. We attempted to minimize this bias by scheduling shifts across days and time periods. We did not systematically collect the number of patients or caregivers who refused participation, but believe that it was less than 5% of those approached. Other limitations include possible reporting biases associated with in‐person interviews, which we attempted to minimize by conducting all surveys in private.

SUMMARY

Identifying needs in patients who utilize the ED soon after being discharged from inpatient care is essential for planning appropriate care‐transition interventions. Our findings suggest that multiple stakeholders may be necessary to fully elicit targets for effective care‐transition programs.