Non-injection drug use patterns and history of injection among street youth.

AIMS Efforts to prevent youth from initiating injection drug use require an understanding of the drug use patterns that predispose to injecting. Here we identify such patterns and describe the circumstances of first injection among street youth. METHODS From October 2005 to November 2007, data were collected for the At Risk Youth Study, a prospective cohort of 560 street-recruited youth aged 14-26 in Vancouver, Canada. Non-injection drug use behaviors were compared between those with and without a history of injection through multiple logistic regression. The circumstances of first injection were also examined in gender-stratified analyses. RESULTS Youth who had previously injected were more likely to have engaged in non-injection use of heroin or of crystal methamphetamine. Daily users of marijuana were less likely to have injected. Among prior injectors, the median age of first injection was lower among females. Females were also more likely to have had a sexual partner present at first injection and to have become a regular injector within one week of initiation. CONCLUSION Preventing transition to injection among street youth may require special attention to predisposing drug use patterns and should acknowledge gender differences in the circumstances of first injection.