Psychosocial factors in adherence to antiretroviral therapy among HIV-positive people who use drugs.

Abstract

Suboptimal adherence to antiretroviral therapy (ART) among HIV-infected people who use illicit drugs (PWUD) remains a significant concern, and there is a lack of effective adherence interventions for this population. Therefore, we sought to identify psychosocial determinants of optimal adherence, including adherence self-efficacy and outcome expectancies, with the aim of informing interventions designed to improve adherence among PWUD. From December 2005 to November 2013, we collected data from the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS), a prospective cohort of PWUD in Vancouver, Canada. We used multivariable generalized estimating equations (GEE) analysis to identify longitudinal factors independently associated with 95% or greater adherence to ART. Among 667 participants, including 220 (33%) women, 391 (59%) had 95% or greater ART adherence at baseline. In multivariable GEE analysis, adherence self-efficacy, adjusted odds ratio (AOR) = 1.16, 95% confidence interval (CI) [1.11, 1.21] per 10-point increase, was independently and positively associated with adherence, while negative outcome expectancy, AOR = 0.95, 95% CI [0.93, 0.98], was negatively associated. In light of the ongoing challenges associated with ART adherence among HIV-positive PWUD, and our findings of associations between adherence, self-efficacy, and outcomes expectancies, tailored intervention strategies based on constructs of social learning theory should be implemented and evaluated to improve adherence among HIV-infected PWUD.