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 Oct 1;61(7):1157-65. doi: 10.1093/cid/civ476. Epub 2015 Jun 25.


Background: Prior studies indicated opioid substitution treatment (OST) reduces mortality risk and improves the odds of accessing highly active antiretroviral therapy (HAART); however, the relative effects of these treatments for human immunodeficiency virus (HIV)-positive people who inject drugs (PWID) are unclear. We determine the independent and joint effects of OST and HAART on mortality, by cause, within a population of HIV-positive PWID initiating HAART.

Methods: Using a linked population-level database for British Columbia, Canada, we used time-to-event analytic methods, including competing risks models, proportional hazards models with time-varying covariates, and marginal structural models, to identify the independent and joint effects of OST and HAART on all-cause as well as drug- and HIV-related mortality, controlling for covariates.

Results: Among 1727 HIV-positive PWID, 493 (28.5%) died during a median 5.1 years (interquartile range, 2.1-9.1) of follow-up: 18.7% due to drug-related causes, 55.8% due to HIV-related causes, and 25.6% due to other causes. Standardized mortality ratios were 12.2 (95% confidence interval [CI], 9.8, 15.0) during OST and 30.0 (27.1, 33.1) during periods out of OST. Both OST (adjusted hazard, 0.34; 95% CI, .23, .49) and HAART (0.39 [0.31, 0.48]) decreased the hazard of all-cause mortality; however, individuals were at lowest risk of death when these medications were used jointly (0.16 [0.10, 0.26]). Both OST and HAART independently protected against HIV-related death, drug-related death and death due to other causes.

Conclusions: While both OST and HAART are life-saving treatments, joint administration is urgently needed to protect against both drug- and HIV-related mortality.

Keywords: HIV/AIDS; highly active antiretroviral therapy; injection drug users; mortality; opioid substitution treatment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antiretroviral Therapy, Highly Active / statistics & numerical data*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Female
  • HIV Infections* / complications
  • HIV Infections* / drug therapy
  • HIV Infections* / mortality
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Opiate Substitution Treatment / statistics & numerical data*
  • Substance Abuse, Intravenous* / complications
  • Substance Abuse, Intravenous* / drug therapy
  • Substance Abuse, Intravenous* / mortality
  • Young Adult