Factors Associated with Syringe Sharing Among Users of a Medically Supervised Safer Injecting Facility

Vancouver, Canada recently opened a medically supervised safer injecting facility (SIF) in an effort to reduce HIV and overdose risk and public injection drug use. We sought to examine factors associated with syringe sharing among SIF users. SIF users were randomly recruited into a prospective cohort of SIF users known as the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. We examined the prevalence and correlates of used syringe borrowing among baseline HIV-negative participants and used syringe lending among baseline HIV-infected participants. Between 22 March 2004 and 22 October 2004, 479 baseline HIV-negative subjects (48 [10%] syringe borrowing events) and 103 baseline HIV-infected participants (17 [16.5%] syringe lending events) were recruited into the cohort. For baseline HIV negative participants, syringe borrowing was positively associated with public drug use (p<0.001) and requiring help injecting (p=0.001), whereas exclusive SIF use was inversely associated with syringe sharing (p=0.019). For baseline HIV-infected participants, syringe lending was positively associated with daily cocaine injection (p=0.022) and shooting gallery use (p=0.007). Although ongoing injection-related HIV risk behavior was reported among some SIF users, rates of syringe sharing were substantially lower than the rate observed previously in this community and it is noteworthy that exclusive SIF use was associated with reduced syringe sharing