Point-of-care HIV viral load in pregnant women without prenatal care: a cost-effectiveness analysis

Abstract

Background: Routine cesarean delivery has been shown to decrease mother-to-child-transmission of HIV in women with high viral load greater than 1000 copies/mL; however, women presenting late in pregnancy may not have viral load results before delivery.

Objective: Our study investigated the costs and outcomes of using a point-of-care HIV RNA viral load test to guide delivery compared with routine cesarean delivery for all in the setting of unknown viral load.

Study design: A decision-analytic model was constructed using TreeAge software to compare HIV RNA viral load testing vs routine cesarean delivery for all in a theoretical cohort of 1275 HIV-positive women without prenatal care who presented at term for delivery, the estimated population of HIV-positive women without prenatal care in the United States annually. TreeAge Pro software is used to build decision trees modeling clinical problems and perform cost-effectiveness, sensitivity, and simulation analysis to identify the optimal outcome. The average cost per test was $15.22. To examine the downstream impact of a cesarean delivery and because most childbearing women in the United States will deliver 2 children, we incorporated a second pregnancy and delivery in the model. Primary outcomes were mother-to-child transmission, delivery mode, cesarean delivery-related complications, cost, and quality-adjusted life years. Model inputs were derived from the literature and varied in sensitivity analyses. The cost-effectiveness threshold was $100,000/quality-adjusted life year.

Results: Measuring viral load resulted in more HIV-infected neonates than routine cesarean delivery for all due to viral exposure during more frequent vaginal births in this strategy. There were no observed maternal deaths or differences in cesarean delivery-related complications. Quantifying viral load increased cost by $3,883,371 and decreased quality-adjusted life years by 63 compared with routine cesarean delivery for all. With the threshold set at $100,000/quality-adjusted life year, the viral load test is cost-effective only when the vertical transmission rate in women with high viral load was below 0.68% (baseline: 16.8%) and when the odds ratio of vertical transmission with routine cesarean delivery for all compared with vaginal delivery was above 0.885 (baseline: 0.3).

Conclusions: For HIV-infected pregnant women without prenatal care, quantifying viral load to guide mode of delivery using a point-of-care test resulted in increased costs and decreased effectiveness when compared with routine cesarean delivery for all, even after including downstream complications of cesarean delivery.

Keywords: HIV testing; biomarker; cesarean; mother-to-child-transmission; point-of-care test; pregnancy outcomes; rapid test; vertical transmission; viral load.