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Maternal screening strategy more effective than risk-based approaches for preventing group B streptococcal disease in neonates
ABSTRACT
BACKGROUND: Group B streptococcal (GBS) infection contributes significantly to neonatal morbidity and mortality. In 1996, the guidelines put forward by the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention (CDC) recommended that prenatal care providers adopt either a “screening” or “risk-based” approach to guide intrapartum antibiotic prophylaxis for neonatal early-onset GBS infection. The efficacy of these 2 alternative approaches in clinical practice was compared in this population-based study.
POPULATION STUDIED: A total of 5144 birth records (including 312 cases of early-onset GBS disease) were randomly selected from 629,912 live birth records in 8 geographic areas monitored by the CDC during 1998 through 1999. The screened and risk-based groups were similar, but the risk-based group had a statistically significant greater number of Hispanics, women with inadequate prenatal care, and preterm deliveries. The screened group had a higher proportion of women with GBS bacteriuria and women with a history of previously delivering a GBS-infected neonate.
STUDY DESIGN AND VALIDITY: In this retrospective cohort study, the authors compared screening and risk-based approaches for prevention of neonatal GBS infection. At least 500 records from each CDC surveillance area were included. All GBS-infected neonates were included in the sample. The sample was stratified by surveillance area, year, and hospital, and each record was given a constant statistical weight based on the inverse of its probability of selection. This weight was adjusted to account for records without charts and for preterm births, ensuring that the number of preterm births was representative of the number in the general population. Abstractors blinded to infant GBS status gathered record information. Women who had a documented GBS culture at least 2 days prior to delivery were included in the screened group, and the remaining women were placed in the risk-based group. Univariate and multivariate analyses were used in comparing the groups, with the infant disease status as the outcome variable.
OUTCOMES MEASURED: The primary outcome measured was early-onset invasive GBS infection in neonates. Abstracters also recorded information on maternal demographics, prenatal care, GBS screening, risk factors for GBS infection, intrapartum antibiotic administration, and gestational age at birth.
RESULTS: The adjusted relative risk of neonatal infection in the screened group compared with the risk-based group was 0.46 (95% confidence interval [CI], 0.36–0.60). Intrapartum fever and a history of a previous infant with early GBS disease were the strongest predictors of GBS disease in both univariate and multivariate analyses. Women in the screened group who had positive culture results were much more likely to receive antibiotic prophylaxis than women in the risk-based group who had risk factors (89% vs 61%, P < .001). However, even with projected perfect administration in the risk-based group, the incidence of GBS disease would still be less in the screened group (0.32 vs 0.44 per 1000 live births). In addition, with perfect implementation of either preventive strategy, the anticipated overall rate of antibiotic use would be similar (31% in the screened group vs 29% in the risk-based group).
Screening is clearly more effective than risk stratification in preventing early-onset neonatal GBS infection. Universal screening for GBS should be adopted. The CDC recently issued updated guidelines that advocate universal screening.1
ABSTRACT
BACKGROUND: Group B streptococcal (GBS) infection contributes significantly to neonatal morbidity and mortality. In 1996, the guidelines put forward by the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention (CDC) recommended that prenatal care providers adopt either a “screening” or “risk-based” approach to guide intrapartum antibiotic prophylaxis for neonatal early-onset GBS infection. The efficacy of these 2 alternative approaches in clinical practice was compared in this population-based study.
POPULATION STUDIED: A total of 5144 birth records (including 312 cases of early-onset GBS disease) were randomly selected from 629,912 live birth records in 8 geographic areas monitored by the CDC during 1998 through 1999. The screened and risk-based groups were similar, but the risk-based group had a statistically significant greater number of Hispanics, women with inadequate prenatal care, and preterm deliveries. The screened group had a higher proportion of women with GBS bacteriuria and women with a history of previously delivering a GBS-infected neonate.
STUDY DESIGN AND VALIDITY: In this retrospective cohort study, the authors compared screening and risk-based approaches for prevention of neonatal GBS infection. At least 500 records from each CDC surveillance area were included. All GBS-infected neonates were included in the sample. The sample was stratified by surveillance area, year, and hospital, and each record was given a constant statistical weight based on the inverse of its probability of selection. This weight was adjusted to account for records without charts and for preterm births, ensuring that the number of preterm births was representative of the number in the general population. Abstractors blinded to infant GBS status gathered record information. Women who had a documented GBS culture at least 2 days prior to delivery were included in the screened group, and the remaining women were placed in the risk-based group. Univariate and multivariate analyses were used in comparing the groups, with the infant disease status as the outcome variable.
OUTCOMES MEASURED: The primary outcome measured was early-onset invasive GBS infection in neonates. Abstracters also recorded information on maternal demographics, prenatal care, GBS screening, risk factors for GBS infection, intrapartum antibiotic administration, and gestational age at birth.
RESULTS: The adjusted relative risk of neonatal infection in the screened group compared with the risk-based group was 0.46 (95% confidence interval [CI], 0.36–0.60). Intrapartum fever and a history of a previous infant with early GBS disease were the strongest predictors of GBS disease in both univariate and multivariate analyses. Women in the screened group who had positive culture results were much more likely to receive antibiotic prophylaxis than women in the risk-based group who had risk factors (89% vs 61%, P < .001). However, even with projected perfect administration in the risk-based group, the incidence of GBS disease would still be less in the screened group (0.32 vs 0.44 per 1000 live births). In addition, with perfect implementation of either preventive strategy, the anticipated overall rate of antibiotic use would be similar (31% in the screened group vs 29% in the risk-based group).
Screening is clearly more effective than risk stratification in preventing early-onset neonatal GBS infection. Universal screening for GBS should be adopted. The CDC recently issued updated guidelines that advocate universal screening.1
ABSTRACT
BACKGROUND: Group B streptococcal (GBS) infection contributes significantly to neonatal morbidity and mortality. In 1996, the guidelines put forward by the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention (CDC) recommended that prenatal care providers adopt either a “screening” or “risk-based” approach to guide intrapartum antibiotic prophylaxis for neonatal early-onset GBS infection. The efficacy of these 2 alternative approaches in clinical practice was compared in this population-based study.
POPULATION STUDIED: A total of 5144 birth records (including 312 cases of early-onset GBS disease) were randomly selected from 629,912 live birth records in 8 geographic areas monitored by the CDC during 1998 through 1999. The screened and risk-based groups were similar, but the risk-based group had a statistically significant greater number of Hispanics, women with inadequate prenatal care, and preterm deliveries. The screened group had a higher proportion of women with GBS bacteriuria and women with a history of previously delivering a GBS-infected neonate.
STUDY DESIGN AND VALIDITY: In this retrospective cohort study, the authors compared screening and risk-based approaches for prevention of neonatal GBS infection. At least 500 records from each CDC surveillance area were included. All GBS-infected neonates were included in the sample. The sample was stratified by surveillance area, year, and hospital, and each record was given a constant statistical weight based on the inverse of its probability of selection. This weight was adjusted to account for records without charts and for preterm births, ensuring that the number of preterm births was representative of the number in the general population. Abstractors blinded to infant GBS status gathered record information. Women who had a documented GBS culture at least 2 days prior to delivery were included in the screened group, and the remaining women were placed in the risk-based group. Univariate and multivariate analyses were used in comparing the groups, with the infant disease status as the outcome variable.
OUTCOMES MEASURED: The primary outcome measured was early-onset invasive GBS infection in neonates. Abstracters also recorded information on maternal demographics, prenatal care, GBS screening, risk factors for GBS infection, intrapartum antibiotic administration, and gestational age at birth.
RESULTS: The adjusted relative risk of neonatal infection in the screened group compared with the risk-based group was 0.46 (95% confidence interval [CI], 0.36–0.60). Intrapartum fever and a history of a previous infant with early GBS disease were the strongest predictors of GBS disease in both univariate and multivariate analyses. Women in the screened group who had positive culture results were much more likely to receive antibiotic prophylaxis than women in the risk-based group who had risk factors (89% vs 61%, P < .001). However, even with projected perfect administration in the risk-based group, the incidence of GBS disease would still be less in the screened group (0.32 vs 0.44 per 1000 live births). In addition, with perfect implementation of either preventive strategy, the anticipated overall rate of antibiotic use would be similar (31% in the screened group vs 29% in the risk-based group).
Screening is clearly more effective than risk stratification in preventing early-onset neonatal GBS infection. Universal screening for GBS should be adopted. The CDC recently issued updated guidelines that advocate universal screening.1
Is once- or twice-a-day enoxaparin as effective as unfractionated heparin for the treatment of venous thromboembolism (VTE)?
BACKGROUND: Several studies have shown that initial treatment with subcutaneous low-molecular-weight heparin is as effective as intravenous unfractionated heparin in preventing the sequelae of VTE. This randomized controlled trial addressed this issue with a large population that included patients with pulmonary embolus (PE).
POPULATION STUDIED: A total of 900 patients from 74 hospitals in 16 countries were enrolled. Subjects were adults with venogram- or ultrasound-proven lower extremity deep venous thrombosis, symptomatic PE with high-probability ventilation-perfusion (V/Q) scan, or a positive angiogram with radiologic evidence of a lower extremity VTE. Exclusion criteria included previous administration of heparin or warfarin for more than 24 hours, risk for hemorrhage, and allergies to the medications or to pork products. The average age was 61 years; 55% were men. Twenty-four percent had had a previous VTE; 16% had cancer; and 32% had a concurrent PE. The study population seems to be similar to that of a family physician., although more information about referral pattern and local diagnostic and therapeutic protocols would be valuable.
STUDY DESIGN AND VALIDITY: This was a randomized unblinded trial. Subjects received 1 of 3 antithrombotic regimens: heparin bolus and continuous infusion to achieve a target activated partial thromboplastin time of 55 to 80 seconds, enoxaparin 1 mg per kg twice daily, or enoxaparin 1.5 mg per kg once daily. These regimens were continued for at least 5 days. Warfarin was started within the first 3 days and was continued for at least 3 months, adjusted to maintain an international normalized ratio between 2.0 and 3.0. All subjects received baseline V/Q scans or angiograms. Although the clinicians were not masked to treatment status, all imaging studies and outcomes were reviewed by committees masked to treatment status. The maker of enoxaparin sponsored and performed the study.
OUTCOMES MEASURED: The major outcomes were recurrence or worsening of VTE or PE, major hemorrhage (ie, >2.0 g/L hemoglobin drop, requiring transfusion of 2 or more units, bleeding requiring intervention, or death), thrombocytopenia, or other side effects. Cost and patient satisfaction were not addressed.
RESULTS: The groups were similar at baseline. There was no significant difference in recurrence or worsening of VTE among patients in the unfractionated heparin group (4.1%), enoxaparin daily group (4.4%), and enoxaparin twice-daily group (2.9%). New PE was rare in all 3 groups (4/900). Regardless of treatment, patients with cancer or symptomatic PE at baseline were at higher risk of subsequent VTE (odds ratio [OR]=3.7; 95% confidence interval [CI], 1.3-11; OR=3.4; 95% CI, 1.55-7.3), respectively. These findings were unchanged when analysis was restricted to subjects for whom all data were available. Similarly, there was no significant difference among the groups in the incidence of major hemorrhage (2.1%, 1.7%, 1.3%, respectively), death (3.1%, 3.7%, 2.2%, respectively), or thrombocytopenia. Adherence to enoxaparin in both groups was better than for unfractionated heparin group (83.6% and 85.3% vs 75.9%, respectively).
This study provides additional evidence that low-molecular-weight heparin is a safe and effective alternative to intravenous unfractionated heparin for initial treatment of acute DVT. For patients for whom outpatient treatment is feasible, enoxaparin is less expensive and is easier to administer than intravenous heparin. These results do not imply that treatment of PE in the outpatient setting is appropriate; likewise, the finding of good results with once-daily dosing is promising but requires confirmation with more rigorous methods. Clinicians should look for studies that address the value of initial overnight hospitalization for VTEs, the impact of the out-of-pocket expense of enoxaparin, and the effectiveness of this intervention in nonclinical trial settings.
BACKGROUND: Several studies have shown that initial treatment with subcutaneous low-molecular-weight heparin is as effective as intravenous unfractionated heparin in preventing the sequelae of VTE. This randomized controlled trial addressed this issue with a large population that included patients with pulmonary embolus (PE).
POPULATION STUDIED: A total of 900 patients from 74 hospitals in 16 countries were enrolled. Subjects were adults with venogram- or ultrasound-proven lower extremity deep venous thrombosis, symptomatic PE with high-probability ventilation-perfusion (V/Q) scan, or a positive angiogram with radiologic evidence of a lower extremity VTE. Exclusion criteria included previous administration of heparin or warfarin for more than 24 hours, risk for hemorrhage, and allergies to the medications or to pork products. The average age was 61 years; 55% were men. Twenty-four percent had had a previous VTE; 16% had cancer; and 32% had a concurrent PE. The study population seems to be similar to that of a family physician., although more information about referral pattern and local diagnostic and therapeutic protocols would be valuable.
STUDY DESIGN AND VALIDITY: This was a randomized unblinded trial. Subjects received 1 of 3 antithrombotic regimens: heparin bolus and continuous infusion to achieve a target activated partial thromboplastin time of 55 to 80 seconds, enoxaparin 1 mg per kg twice daily, or enoxaparin 1.5 mg per kg once daily. These regimens were continued for at least 5 days. Warfarin was started within the first 3 days and was continued for at least 3 months, adjusted to maintain an international normalized ratio between 2.0 and 3.0. All subjects received baseline V/Q scans or angiograms. Although the clinicians were not masked to treatment status, all imaging studies and outcomes were reviewed by committees masked to treatment status. The maker of enoxaparin sponsored and performed the study.
OUTCOMES MEASURED: The major outcomes were recurrence or worsening of VTE or PE, major hemorrhage (ie, >2.0 g/L hemoglobin drop, requiring transfusion of 2 or more units, bleeding requiring intervention, or death), thrombocytopenia, or other side effects. Cost and patient satisfaction were not addressed.
RESULTS: The groups were similar at baseline. There was no significant difference in recurrence or worsening of VTE among patients in the unfractionated heparin group (4.1%), enoxaparin daily group (4.4%), and enoxaparin twice-daily group (2.9%). New PE was rare in all 3 groups (4/900). Regardless of treatment, patients with cancer or symptomatic PE at baseline were at higher risk of subsequent VTE (odds ratio [OR]=3.7; 95% confidence interval [CI], 1.3-11; OR=3.4; 95% CI, 1.55-7.3), respectively. These findings were unchanged when analysis was restricted to subjects for whom all data were available. Similarly, there was no significant difference among the groups in the incidence of major hemorrhage (2.1%, 1.7%, 1.3%, respectively), death (3.1%, 3.7%, 2.2%, respectively), or thrombocytopenia. Adherence to enoxaparin in both groups was better than for unfractionated heparin group (83.6% and 85.3% vs 75.9%, respectively).
This study provides additional evidence that low-molecular-weight heparin is a safe and effective alternative to intravenous unfractionated heparin for initial treatment of acute DVT. For patients for whom outpatient treatment is feasible, enoxaparin is less expensive and is easier to administer than intravenous heparin. These results do not imply that treatment of PE in the outpatient setting is appropriate; likewise, the finding of good results with once-daily dosing is promising but requires confirmation with more rigorous methods. Clinicians should look for studies that address the value of initial overnight hospitalization for VTEs, the impact of the out-of-pocket expense of enoxaparin, and the effectiveness of this intervention in nonclinical trial settings.
BACKGROUND: Several studies have shown that initial treatment with subcutaneous low-molecular-weight heparin is as effective as intravenous unfractionated heparin in preventing the sequelae of VTE. This randomized controlled trial addressed this issue with a large population that included patients with pulmonary embolus (PE).
POPULATION STUDIED: A total of 900 patients from 74 hospitals in 16 countries were enrolled. Subjects were adults with venogram- or ultrasound-proven lower extremity deep venous thrombosis, symptomatic PE with high-probability ventilation-perfusion (V/Q) scan, or a positive angiogram with radiologic evidence of a lower extremity VTE. Exclusion criteria included previous administration of heparin or warfarin for more than 24 hours, risk for hemorrhage, and allergies to the medications or to pork products. The average age was 61 years; 55% were men. Twenty-four percent had had a previous VTE; 16% had cancer; and 32% had a concurrent PE. The study population seems to be similar to that of a family physician., although more information about referral pattern and local diagnostic and therapeutic protocols would be valuable.
STUDY DESIGN AND VALIDITY: This was a randomized unblinded trial. Subjects received 1 of 3 antithrombotic regimens: heparin bolus and continuous infusion to achieve a target activated partial thromboplastin time of 55 to 80 seconds, enoxaparin 1 mg per kg twice daily, or enoxaparin 1.5 mg per kg once daily. These regimens were continued for at least 5 days. Warfarin was started within the first 3 days and was continued for at least 3 months, adjusted to maintain an international normalized ratio between 2.0 and 3.0. All subjects received baseline V/Q scans or angiograms. Although the clinicians were not masked to treatment status, all imaging studies and outcomes were reviewed by committees masked to treatment status. The maker of enoxaparin sponsored and performed the study.
OUTCOMES MEASURED: The major outcomes were recurrence or worsening of VTE or PE, major hemorrhage (ie, >2.0 g/L hemoglobin drop, requiring transfusion of 2 or more units, bleeding requiring intervention, or death), thrombocytopenia, or other side effects. Cost and patient satisfaction were not addressed.
RESULTS: The groups were similar at baseline. There was no significant difference in recurrence or worsening of VTE among patients in the unfractionated heparin group (4.1%), enoxaparin daily group (4.4%), and enoxaparin twice-daily group (2.9%). New PE was rare in all 3 groups (4/900). Regardless of treatment, patients with cancer or symptomatic PE at baseline were at higher risk of subsequent VTE (odds ratio [OR]=3.7; 95% confidence interval [CI], 1.3-11; OR=3.4; 95% CI, 1.55-7.3), respectively. These findings were unchanged when analysis was restricted to subjects for whom all data were available. Similarly, there was no significant difference among the groups in the incidence of major hemorrhage (2.1%, 1.7%, 1.3%, respectively), death (3.1%, 3.7%, 2.2%, respectively), or thrombocytopenia. Adherence to enoxaparin in both groups was better than for unfractionated heparin group (83.6% and 85.3% vs 75.9%, respectively).
This study provides additional evidence that low-molecular-weight heparin is a safe and effective alternative to intravenous unfractionated heparin for initial treatment of acute DVT. For patients for whom outpatient treatment is feasible, enoxaparin is less expensive and is easier to administer than intravenous heparin. These results do not imply that treatment of PE in the outpatient setting is appropriate; likewise, the finding of good results with once-daily dosing is promising but requires confirmation with more rigorous methods. Clinicians should look for studies that address the value of initial overnight hospitalization for VTEs, the impact of the out-of-pocket expense of enoxaparin, and the effectiveness of this intervention in nonclinical trial settings.