A randomized clinical trial of community-based directly observed therapy as an adherence intervention for HAART among substance users

Abstract

Adherence interventions for HAART can impact challenging populations, such as active substance users. Community-based modified directly observed therapy (MDOT) is a promising approach that needs to be critically evaluated. This study was a randomized clinical trial. HIV seropositive substance users were randomized to either standard of care (SOC) or MDOT, stratified by HAART experience. All participants were placed on a once-daily regimen and were met by an outreach worker for all 7 days during the first 3 months. We used an intent-to-treat analysis to evaluate differences in viral load suppression [> 2 log drop in plasma viral load (PVL) or PVL < 50] and changes in PVL and CD4 cell count from baseline to 3 months. A total of 87 participants were enrolled (43 in SOC, 44 in MDOT), Using repeated measures logistic regression, MDOT participants were more likely to achieve PVL suppression (odds ratio, 2.16; 95% confidence interval, 1.0-4.7), driven primarily by those HAART experienced (odds ratio, 2.88; 95% confidence interval, 1.2-7.0). A significant treatment effect was also found in CD4 cell count change (P < 0.05). No differences were found by arm in undetectable PVL. This study provides evidence that MDOT is an effective strategy to reduce viral load and increase CD4 cell counts in HAART experienced substance users. MDOT should be included in the spectrum of options to enhance adherence in this population.