Correlation of Adherence by Pill Count, Self-report, MEMS and Plasma Drug Levels to Treatment Response Among Women Receiving ARV Therapy for PMTCT in Kenya.

Success of antiretroviral therapy depends on adherence to effective treatment. We evaluated four adherence methods and their correlation with immunological and virologic response among women receiving PMTCT. Univariable and multivariable analyses were used to assess how adherence by pill count (n = 463), self-report (n = 463), MEMS (n = 129) and plasma drug level (n = 89) was associated with viral load suppression within a 6 months period. Longitudinal analysis was performed to determine the correlation of CD4 cell count with each measure of adherence. For all measures of adherence, sustained viral suppression was less likely for participants in the lowest category of adherence. Although CD4 cell count increased substantially over time, there was no significant association with adherence by the methods. Multiple strategies can be used successfully to monitor treatment adherence. Persons with ≥95% adherence by any method used in this study were more likely to have a favorable treatment outcome.