Antiretroviral use and pharmacy-based measurement of adherence in postpartum HIV-infected women

BACKGROUND. Antiretroviral treatment for HIV-infected women is standard during pregnancy to prevent vertical transmission, but data on postpartum therapy for the mother are lacking. OBJECTIVE. The objective of this study was to examine the impact of provider and patient characteristics on receipt of antiretroviral therapy and pharmacy-based measurement of adherence by postpartum HIV-infected women. RESEARCH DESIGN. This was a retrospective cohort study. SUBJECTS. The study included 2,648 New York State Medicaid-enrolled HIV-infected women who delivered from January 1993 through October 1996 and were followed up through September 1997. MEASURES. From Medicaid claims in the first postpartum year, the study examined any prescribed antiretroviral therapy and, among women treated >2 months, adherence, defined as greater than or equal to 80% days covered by prescribed therapy from first to last antiretroviral prescription. RESULTS. Antiretroviral therapy was prescribed for 681 (26%) study women. Of 292 women treated >2 months, 28% were adherent on the basis of the pharmacy-based measure. The proportion of treated women was highest in 1996 (40%), and adherence was best in 1995 (44%) when most women took monotherapy. The adjusted odds ratios (AORs) of treatment were 1.67 (95% CI, 1.24 to 2.25) for women receiving HIV-focused services and 2.71 (95% CI, 1.99 to 3.69) for women with a provider in an HIV-related specialty. The AORs of adherence were greater for women with HIV-focused services (2.13; 95% CI, 1.05 to 4.30) and for former illicit drug users versus nonusers (2.40; 95% CI, 1.05 to 5.50). CONCLUSIONS. This population-based pharmacy analysis reveals improving antiretroviral use but continuing poor pharmacy-based adherence by postpartum HIV-infected women. Receipt of HIV-focused services appears to be particularly beneficial in increasing the likelihood of treatment and adherence.