Adherence to antiretroviral therapy by pregnant women infected with human immunodeficiency virus: a pharmacy claims-based analysis.

OBJECTIVE: To assess adherence to antiretroviral therapy with the use of Medicaid pharmacy claims data for human immunodeficiency virus (HIV)-infected pregnant women and to identify associated maternal and health care factors.
METHODS: We retrospectively studied a cohort of 2714 HIV-infected women in New York State who delivered live infants from 1993-96. Among 682 women prescribed antiretroviral therapy in the last two trimesters, we studied 549 who started therapy more than 2 months before delivery. Adherence was defined as adequate if the supplied drug covered at least 80% of the days from the first prescription in the last two trimesters until delivery. Multivariable analyses were used to examine associations between maternal and health care factors and adherence.
RESULTS: Only 34.2% of 549 subjects had at least 80% adherence based on pharmacy data, a rate that remained stable over time. The adjusted odds ratios (ORs) of adherence for black (OR 0.47, 95% confidence interval [CI] 0.30, 0.75) and Hispanic (OR 0.49, 95% CI 0.29, 0.82) women were nearly 50% lower than for white women. The OR of adherence was 0.32 (95% CI 0.12, 0.90) for teenagers compared with women aged 25-29 years and 0.56 (95% CI 0.34, 0.92) for women in New York City versus those residing elsewhere. Women on antiretroviral therapy before pregnancy were more likely to adhere (OR 1.55, 95% CI 1.02, 2.35).
CONCLUSION: Teenagers, women of minority groups, and women living in New York City had greater risks of poor antiretroviral adherence, whereas women already prescribed antiretrovirals before pregnancy had better adherence. Our conservative pharmacy data-based measure showed that most HIV-infected women adhered poorly and adherence did not improve over the 4-year study.