Routine antenatal thrombophilia screening in high-risk pregnancies: a decision analysis.

Thrombophilias have been implicated in complications related to ischemic placental disease including recurrent pregnancy loss, intrauterine fetal demise, preeclampsia, fetal growth restriction, placental abruption, and preterm delivery. Maternal screening and treatment may lower the recurrence of these outcomes. Our objective was to estimate if antenatal screening for thrombophilias with the intention to offer treatment among women with a prior adverse pregnancy outcome (APO) is preferable to no screening. A decision-analytical model was constructed for pregnant women with prior APO, comparing screening for thrombophilia with intention to treat with no screening. Values obtained from previously published studies include probability of positive test: 0.3 (0.1 to 0.6); good outcome with treatment: 0.9 (0.3 to 0.99); no thrombophilia, good outcome: 0.75 (0.5 to 0.9); test negative, thrombophilia positive: 0.05 (0.01 to 0.1); test negative, thrombophilia positive, good outcome: 0.75 (0.5 to 0.9); thrombophilia/test negative, good outcome: 0.98 (0.5 to 0.99). Sensitivity analyses were run over a wide range of assumptions. Thrombophilia screening with intention to treat in women with prior APO associated with ischemic placental disease is the strategy of choice compared with no testing over a wide range of assumptions. Sensitivity analyses support this to be robust. Women with poor pregnancy history related to placental ischemic disease may benefit from thrombophilia screening and treatment in a subsequent pregnancy.

Rapid HIV versus enzyme-linked immunosorbent assay screening in a low-risk Mexican American population presenting in labor: a cost-effectiveness analysis.

OBJECTIVE: Mother-to-child transmission of human immunodeficiency virus is the most common cause of pediatric human immunodeficiency virus in the United States; the Centers for Disease Control and Prevention recommendations endorse rapid human immunodeficiency virus testing for women with unknown viral status to quicken antiretroviral therapy. We compared the cost-effectiveness of Oraquick (Orasure Technologies, Bethlehem, Pa) rapid testing versus enzyme-linked immunosorbent assay testing for a low-risk population of Mexican American women who are in labor. STUDY DESIGN: Using decision analysis techniques, we tested 2 strategies: (1) testing with enzyme-linked immunosorbent assay that was confirmed by Western blot and (2) testing with Oraquick rapid testing that was confirmed by Western blot. All seropositive parturients received zidovudine treatment in labor. The baseline assumptions were the incidence of human immunodeficiency virus in Mexican American mothers (0.05%), mother-to-child transmission with no treatment (25%), with treatment in labor (10%), sensitivity of enzyme-linked immunosorbent assay (98%), positive predictive value of enzyme-linked immunosorbent assay (10%), sensitivity/specificity of Oraquick rapid testing (99%/100%), positive predictive value of Oraquick rapid testing (83%-100%), sensitivity/specificity of Western blot (97%/99%), costs (enzyme-linked immunosorbent assay [dollar 5], Oraquick rapid testing [dollar 15], Western blot [dollar 25], zidovudine treatment [dollar 76] for 12 hours labor, neonatal treatment [dollar 2.50], lifetime treatment of human immunodeficiency virus-affected child [dollar 194,250]). Sensitivity analyses were done over a wide range of assumptions that included the costs of tests, the sensitivity of Oraquick rapid testing, the positive predictive value of enzyme-linked immunosorbent assay and Oraquick rapid testing, and the costs of treatments. RESULTS: Oraquick rapid testing was the preferred strategy at dollar 98 spent per human immunodeficiency virus-negative child versus dollar 491 for enzyme-linked immunosorbent assay testing. Much of the cost of the enzyme-linked immunosorbent assay strategy was due to the treatment of women and infants with false-positive tests. Sensitivity analysis over test costs, test sensitivity, and other variables found the analysis results to be robust. Threshold analysis revealed that, if the cost remained < dollar 409.90, Oraquick rapid testing was the dominant test. CONCLUSION: In a low prevalence population, the universal use of Oraquick rapid testing is cost-effective because of the low rate of false-positive results, thus preventing the emotional and economic costs of unnecessary treatment for human immunodeficiency virus to the new mother and her family.

Diagnosis of pulmonary embolism: a cost-effectiveness analysis.

OBJECTIVE: Pulmonary embolism is a major cause of maternal death. The work up for suspected pulmonary embolism is complex, with many potential diagnostic options. We performed a cost analysis to evaluate which of several diagnostic strategies was the most cost-effective with the least number of deaths from pulmonary embolism. STUDY DESIGN: We created a decision tree to evaluate the following strategies: (1) Compression ultrasonography followed by anticoagulation (if there is a positive result) or secondary tests, ventilation perfusion scans or spiral computed tomography (if there is a negative result); high probability ventilation perfusion scans (a positive test result) resulted in anticoagulation; low probability ventilation perfusion scans (a negative test) resulted in no treatment; intermediate tests that resulted in a second test (computed tomography or pulmonary angiography). (2) Ventilation perfusion scans as a primary test followed by anticoagulation. (3) Computed tomography followed by anticoagulation (if there is a positive result). The following assumptions were made: The incidence of pulmonary embolism in pregnant women with suspected pulmonary embolism is 5%; 40% of documented pulmonary embolisms have a positive compression ultrasound result; 10% of ventilation perfusion scans for suspected pulmonary embolism are high probability, 60% are indeterminate, and 30% are low probability for pulmonary embolism; the sensitivity of computed tomography is 95%; the sensitivity of angiography is 98%. The assumed mortality rate of treated pulmonary embolism is 0.7% and of untreated pulmonary embolism in pregnancy is 15% (range, 10%-50%). The angiography-associated mortality rate is 0.5%, and the anticoagulation associated mortality rate is 0.2%. The following costs were used for the model: compression ultrasonography, 200.00 dollars; ventilation perfusion scans, 400.00 dollars; angiography, 1000.00 dollars; computed tomography, 500.00 dollars; and anticoagulation, 5982.00 dollars. With baseline assumptions, spiral computed tomography as the initial diagnostic regimen was found to be the most cost-effective at 17,208 dollars per life saved. Sensitivity analyses were performed over a wide range of assumptions that included alteration of the probability of pulmonary embolism, the sensitivity of computed tomography, ventilation perfusion scans, and compression ultrasonography, the cost of computed tomography, and the mortality rate of untreated pulmonary embolism. Our findings remained robust over a wide range of assumptions. CONCLUSION: Suspected pulmonary embolism remains a diagnostic quandary. Our analysis indicated that spiral computed tomography offers the most cost-effective method for diagnosing this potentially fatal condition.

Prenatal cystic fibrosis screening in Mexican Americans: an economic analysis.

OBJECTIVE: We evaluated the cost benefit of cystic fibrosis screening in Mexican American gravid women. STUDY DESIGN: With the use of decisions analysis techniques, a cost-benefit analysis was performed. Baseline assumptions were based on published references. Sensitivity analyses were performed. RESULTS: Under the baseline assumptions, screening was not cost beneficial. Threshold analysis showed that, if the test was priced under 53.00 dollars, screening became cost beneficial. Sensitivity analysis demonstrated that lower acceptance rates of amniocentesis or termination made the screening strategy less attractive. If the test sensitivity was raised to 90%, which required testing of >60 mutations, the cost of screening would need to be <100.00 dollars for the program to be cost beneficial. CONCLUSION: Cystic fibrosis screening is not cost beneficial in Mexican American women over a wide range of assumptions. This is principally due to the poor sensitivity of the test in this population. Cultural factors, such as lower acceptance of amniocentesis and pregnancy termination of affected fetuses, further lower the cost-benefit ratio of screening.