Receipt of Both Antiretroviral Therapy and Opioid Agonist Therapy Associated with Decreased Mortality Among People with HIV and Injection Drug Use

The pathways by which antiretroviral therapy (ART) and opioid agonist therapy (OAT) impact drug and HIV-related mortality are interrelated and complex. This prospective cohort study investigated all-cause and cause-specific mortality among 1727 Canadians with HIV and a history of injection drug use (IDU) receiving OAT and ART alone and concurrently between January 1996 and March 2010. Participants initiated ART at study enrollment.

• At baseline, 35% of participants were receiving OAT.
• Over the 14-year study period, 29% of participants died.
• In marginal structural models, the hazard of all-cause mortality was significantly reduced in individuals receiving ART (hazard ratio [HR], 0.39) and OAT (HR, 0.34).
• ART was negatively associated with drug-related deaths (HR, 0.49), while OAT was not. ART and OAT were both negatively associated with HIV-related deaths (HR, 0.34 and 0.33, respectively) and death from other causes (HR, 0.37 and 0.45).
• The greatest reductions were in individuals receiving both ART and OAT (all-cause mortality HR, 0.16; drug-related HR, 0.40; HIV-related HR, 0.14; other causes HR, 0.08).

Comments:

In this observational study, patients receiving OAT may have more severe substance use disorders than patients not receiving OAT, increasing their risk of death compared with others with a remote history of IDU. On the other hand, this study may underestimate the contemporary impact of OAT on mortality, as the models do not account for increasing tolerability and effectiveness of ART over the study period, and OAT is known to lead to improved ART adherence. These findings are particularly noteworthy because ART is widely available to individuals with HIV in resource-rich settings; effective strategies targeted at expanding access to OAT (e.g., HIV clinic-based buprenorphine) are needed. Finally, it is important to note the limitations of accurately determining cause-specific mortality, especially drug-related mortality, in observational studies.

Jessica S. Merlin, MD, MBA

Reference:

Nosyk B, Min JE, Evans E, et al. The effects of opioid substitution treatment and highly active antiretroviral therapy on the cause-specific risk of mortality among HIV-positive people who inject drugs. Clin Infect Dis. 2015;61(7):1157–1165.