Does initiation of HIV antiretroviral therapy influence patterns of syringe lending among injection drug users?

The delivery of antiretroviral therapy (ART) to injection drug users (IDU) may be influenced by provider concerns regarding the potential for increased HIV-related risk behavior following the initiation of HIV treatment. We evaluated whether ART initiation was associated with changes in syringe lending patterns among a long-term prospective cohort of HIV-positive IDU in Vancouver, Canada. Among 380 ART-naïve individuals eligible for this analysis, the median age was 34.2 (interquartile range [IQR] 27.7-40.8), 171 (45.0%) were female, and the median follow-up duration was 60 months (IQR=18-113). Between May 1996 and April 2008, 260 (68.4%) participants initiated ART. In a generalized linear mixed-effects model which compared each individual's likelihood of sharing syringes prior to and following the initiation of ART, syringe lending was not significantly associated with ART initiation in unadjusted (odds ratio=0.72, 95% CI: 0.38-1.36) or adjusted (odds ratio=0.78, 95% CI: 0.42-1.45) analyses. Concerns regarding increased injection risk behaviors following the initiation of ART were not observed in this setting.