PurposeThis 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.

Homelessness Independently Predicts Injection Drug Use Initiation Among Street-Involved Youth in a Canadian Setting was published in the Journal of Adolescent Health, 52(4): 499-501, 2013