Objectives: The aim of the study was to quantify the benefits (life expectancy gains) and risks (efavirenz-related teratogenicity) associated with using efavirenz in HIV-infected women of childbearing age in the USA.
Methods: We used data from the Women's Interagency HIV Study in an HIV disease simulation model to estimate life expectancy in women who receive an efavirenz-based initial antiretroviral regimen compared with those who delay efavirenz use and receive a boosted protease inhibitor-based initial regimen. To estimate excess risk of teratogenic events with and without efavirenz exposure per 100,000 women, we incorporated literature-based rates of pregnancy, live births, and teratogenic events into a decision analytic model. We assumed a teratogenicity risk of 2.90 events/100 live births in women exposed to efavirenz during pregnancy and 2.68/100 live births in unexposed women.
Results: Survival for HIV-infected women who received an efavirenz-based initial antiretroviral therapy (ART) regimen was 0.89 years greater than for women receiving non-efavirenz-based initial therapy (28.91 vs. 28.02 years). The rate of teratogenic events was 77.26/100,000 exposed women, compared with 72.46/100,000 unexposed women. Survival estimates were sensitive to variations in treatment efficacy and AIDS-related mortality. Estimates of excess teratogenic events were most sensitive to pregnancy rates and number of teratogenic events/100 live births in efavirenz-exposed women.
Conclusions: Use of non-efavirenz-based initial ART in HIV-infected women of childbearing age may reduce life expectancy gains from antiretroviral treatment, but may also prevent teratogenic events. Decision-making regarding efavirenz use presents a trade-off between these two risks; this study can inform discussions between patients and health care providers.