Adherence to antiretroviral therapy among HIV-infected drug users: a meta-analysis.

We conducted a meta-analysis of studies assessing adherence to highly active antiretroviral therapy (HAART) and a qualitative systematic review of factors associated with better HAART outcomes among HIV+ drug users (DU). Thirty-eight studies were considered, which analyzed 14,960 patients (11,394 HIV+ DU, 76.2%). Overall adherence (pooled percent of DU classified as adherent in each study) was 0.60 (95% CI: 0.52-0.68), similar to levels identified by studies conducted with HIV+ patients who are not drug users. Time frame used to measure adherence was an independent predictor of inter-study heterogeneity. The systematic review identified better HAART outcomes among former DU, those with less severe psychiatric conditions, those receiving opioid substitution therapy and/or psychosocial support. Patients initiating HAART with lower viral load and higher CD4 counts, and those without co-infections also had better treatment outcomes. Our findings suggest that HIV+ DU tend to be inappropriately assumed to be less adherent and unlikely to achieve desirable treatment outcomes, when compared to their non-DU cohort.