Antiretroviral Therapy Adherence and Viral Suppression in HIV‐Infected Drug Users: Comparison of Self‐Report and Electronic Monitoring

TLDR

The study compared electronically monitored (MEMS) and self‑reported antiretroviral adherence and their association with HIV viral load in 67 drug‑using patients over six months. Adherence was quantified as the percentage of prescribed doses taken during the day and week before each of six scheduled visits, using both MEMS caps and self‑report questionnaires. Self‑reported adherence averaged 79% (1‑day) and 78% (1‑week) versus 57% and 53% for MEMS; both measures correlated with HIV load, but high MEMS adherence more strongly predicted virologic suppression, indicating MEMS is more sensitive for detecting nonadherence.

Abstract

To compare electronically monitored (MEMS) with self-reported adherence in drug users, including the impact of adherence on HIV load, we conducted a 6-month observational study of 67 antiretroviral-experienced current and former drug users. Adherence (percentage of doses taken as prescribed) was calculated for both the day and the week preceding each of 6 research visits. Mean self-reported 1-day adherence was 79% (median, 86%), and mean self-reported 1-week adherence was 78% (median, 85%). Mean MEMS 1-day adherence was 57% (median, 52%), and mean MEMS 1-week adherence was 53% (median, 49%). One-day and 1-week estimates were highly correlated (r > .8 for both measures). Both self-reported and MEMS adherence were correlated with concurrent HIV load (r = .43–.60), but the likelihood of achieving virologic suppression was greater if MEMS adherence was high than if self-reported adherence was high. We conclude that self-reported adherence is higher than MEMS adherence, but a strong relationship exists between both measures and virus load. However, electronic monitoring is more sensitive than self-report for the detection of nonadherence and should be used in adherence intervention studies.