Assessing the Temporality Between Transitions onto Opioid Agonist Therapy and Engagement with Antiretroviral Therapy in a Cohort of HIV-Positive People Who Use Opioids Daily.

A robust evidence-base describes the beneficial association between opioid agonist therapy (OAT) and HIV-related outcomes among people living with HIV and opioid use disorder. While some evidence suggests the stabilizing effect of OAT on antiretroviral therapy (ART) treatment engagement, less is understood about the potential for an inverse relationship. We sought to examine the relationship between transitions in ART engagement and transitions onto OAT. We used data from a prospective cohort of people living with HIV who use drugs in Vancouver, Canada-a setting with no-cost access to ART and low or no-cost access to OAT among low-income residents. Restricting the sample to those who reported daily or greater opioid use, we used generalized linear mixed-effects models to estimate the relationships between our primary outcome of transitions onto OAT (methadone or buprenorphine/naloxone) and transitions (1) onto ART and (2) into ART adherence. Subsequent analyses assessed the temporal sequencing of transitions. Between 2005 and 2017, among 433 participants, 48.3% reported transitioning onto OAT at least once. In concurrent analyses, transitions onto ART were positively and significantly associated with transitions onto OAT. Temporal sequencing revealed that transitions into OAT were also positively and significantly associated with subsequent transitions onto ART. OAT's potential to facilitate the uptake of ART points to the continued need to scale-up low-threshold, client-centered substance use services integrated alongside HIV care.