Low Adherence to ARV among HIV-Infected Pregnant Women in rural South Africa

Abstract

Background. Adherence to antiretroviral (ARV) therapy is an essential component of Prevention of Mother to Child Transmission (PMTCT). South African PMTCT first ARV line regimens are TDF + 3TC (or FTC) + EFV. Dried blood spots (DBS) accurately measure ARV adherence and predict risk for perinatal infection in PMTCT programs. This study evaluated DBS ARV adherence in HIV infected pregnant women in rural South Africa. Methods. Participants (N = 373) were HIV-infected women on first line regimens at week 32 of pregnancy recruited from rural clinics. Women completed demographic and self-reported ARV adherence assessments (7-day Visual Analog Scale [VAS], and skipped medication in the past week). If no missed doses were reported, responses were coded as adherent; all other responses were coded as nonadherent. DBS ARV (TDF, 3TC, and EFV) adherence was assessed and dichotomously coded as detectable or undetectable. Adherence was defined as 3 drugs detected or TDF + EFV detected. Nonadherence was defined as no detectable ARV, one ARV detectable, or two ARVs that were not TDF + EFV detectable. Results. Median age was 28 +/- 6; 39% of women had monthly income less than $32, 78% were unemployed, and 52% had completed at least 10 years of education. DBS ARV detection was as follows: adherent = 74% (2% TDF + 3TC + EFV and 72% TDF + EFV); nonadherent = 26% (11% no ARV, 11% 1 ARV, and 4% 2 ARVs that were not TDF + EFV). Overall proportions of adherent participants were similar across measures: 69% (VAS), 71% (skipped medication), and 74% (DBS). However, intermeasure agreement was low between the number of skips and DBS testing VAS (kappa = 0.053), and the VAS and DBS testing (kappa = 0.054) such that participants who had nondetectable levels of ARVs were categorized as adherent by self-report measures. Conclusion. Detectable levels of ARV were suboptimal in pregnant HIV infected women in rural South Africa, indicating a risk of perinatal HIV infection and development of resistance. Programs to improve ARV adherence in this population are urgently needed. Findings suggest that self-reported adherence measures do not correlate with biological markers in this population. Validation of self-reported ARV adherence among pregnant HIV infected women in South Africa may be warranted to support PMTCT outcomes.