Homelessness independently predicts injection drug use initiation among street-involved youth in a Canadian setting.

PURPOSE This longitudinal study examines the association between homelessness and injection drug use initiation among a cohort of street-involved youth in a setting of high-prevalence crystal methamphetamine use. METHODS We derived data from the At-Risk Youth Study, a prospective cohort of street-involved youth aged 14-26 years, recruited between September 2005 and November 2011. We used Cox proportional hazards regression to identify factors independently associated with time to injection initiation. RESULTS Among 422 street-youth who had never injected at baseline, we observed 77 injection initiation events during follow-up. Homelessness was independently associated with injection initiation in multivariate Cox regression (relative hazard, 1.80 [95% confidence interval, 1.13-2.87]) after adjusting for crystal methamphetamine use and other potential confounders. CONCLUSIONS These findings highlight that homelessness is a key risk factor for injection initiation among street-involved youth. Supportive housing interventions for street youth may help prevent injection drug use initiation within this high-risk population.