Directly observed antiretroviral therapy improves adherence and viral load in drug users attending methadone maintenance clinics: a randomized controlled trial

Abstract

Objective: To determine if directly observed antiretroviral therapy (DOT) is more efficacious than self-administered therapy for improving adherence and reducing HIV viral load (VL) among methadone-maintained opioid users.

Design: Two-group randomized trial.

Setting: Twelve methadone maintenance clinics with on-site HIV care in the Bronx, New York.

Participants: HIV-infected adults prescribed combination antiretroviral therapy.

Main outcomes measures: Between group differences at four assessment points from baseline to week 24 in: (1) antiretroviral adherence measured by pill count, (2) VL, and (3) proportion with undetectable VL (< 75 copies/ml).

Results: Between June 2004 and August 2007, we enrolled 77 participants. Adherence in the DOT group was higher than in the control group at all post-baseline assessment points; by week 24 mean DOT adherence was 86% compared to 56% in the control group (p < 0.0001). Group differences in mean adherence remained significant after stratifying by baseline VL (detectable versus undetectable). In addition, during the 24-week intervention, the proportion of DOT participants with undetectable VL increased from 51% to 71%.

Conclusions: Among HIV-infected opioid users, antiretroviral DOT administered in methadone clinics was efficacious for improving adherence and decreasing VL, and these improvements were maintained over a 24-week period. DOT should be more widely available to methadone patients.

Figure 1

Flow chart of study recruitment, enrollment, and completion.

Figure 2a

Differences in mean pill count adherence rates by study arm at each assessment point during the 24-week intervention period. Precise estimates available in online supplementary materials. DOT: directly observed therapy; TAU: treatment as usual *p < 0.01, based on mixed effects model analysis.

Figure 2b

Differences in mean pill count adherence rates by study arm at each assessment point during the 24-week intervention period, stratified by baseline viral load (≥75 copies/ml versus <75 copes/ml). Precise estimates available in online supplementary materials. DOT: directly observed therapy; TAU: treatment as usual; VL: viral load *p < 0.01 for difference between DOT and TAU among participants with undetectable baseline VL. †p < 0.01 for difference between DOT and TAU among participants with detectable baseline VL. All p values based on mixed effects model analysis.

Figure 3a

Differences in log₁₀ viral load by study arm at each assessment point during the 24-week intervention period. Precise estimates available in online supplementary materials. DOT: directly observed therapy; TAU: treatment as usual; VL: viral load *p <0.01 based on mixed effects model analysis

Figure 3b

Differences in log₁₀ viral load by study arm at each assessment point during the 24-week intervention period, stratified by baseline viral load (≥75 copies/ml versus <75 copes/ml). Precise estimates available in online supplementary materials. DOT: directly observed therapy; TAU: treatment as usual; VL: viral load *p<0.02 for difference between DOT and TAU among participants with detectable baseline VL, based on mixed effects model analysis.

Figure 4

Proportions of participants with undetectable viral load (<75 copies/ml) by study arm at each assessment point during the 24-week intervention period. Precise estimates available in online supplementary materials. DOT: directly observed therapy; TAU: treatment as usual