Lack of Sustained Improvement in Adherence or Viral Load Following a Directly Observed Antiretroviral Therapy Intervention

Background. Methadone clinic-based directly observed antiretroviral therapy (DOT) has been shown to be more efficacious for improving adherence and suppressing human immunodeficiency virus (HIV) load than antiretroviral self-administration. We sought to determine whether the beneficial effects of DOT remain after DOT is discontinued. Methods. We conducted a post-trial cohort study of 65 HIV-infected opioid-dependent adults who had completed a 24-week randomized controlled trial of methadone clinic-based DOT versus treatment as usual (TAU). For 12 months after DOT discontinuation, we assessed antiretroviral adherence using monthly pill counts and electronic monitors. We also assessed viral load at 3, 6, and 12 months after DOT ended. We examined differences between DOT and TAU in (1) adherence, (2) viral load, and (3) proportion of participants with viral load of <75 copies/mL. Results. At trial end, adherence was higher among DOT participants than among TAU participants (86% and 54%, respectively; P < .001), and more DOT participants than TAU participants had viral loads of <75 copies/mL (71% and 44%, respectively; P = .03). However, after DOT ended, differences in adherence diminished by 1 month (55% for DOT vs 48% for TAU; P = .33) and extinguished completely by 3 months (49% for DOT vs 50% for TAU; P = .94). Differences in viral load between DOT and TAU disappeared by 3 months after the intervention, and the proportion of DOT participants with undetectable viral load decreased steadily after DOT was stopped until there was no difference (36% for DOT and 34% for TAU; P = .92). Conclusions. Because the benefits of DOT for adherence and viral load among HIV-infected methadone patients cease after DOT is stopped, methadone-based DOT should be considered a long-term intervention.