Risk Factors for Progression to Regular Injection Drug Use among Street-Involved Youth in a Canadian Setting

Background Street-involved youth are at high risk for experimenting with injection drug use; however, little attention has been given to identifying the factors that predict progression to on-going injecting. Methods Logistic regression was used to identify factors associated with progression to injecting weekly on a regular basis among a Canadian cohort of street-involved youth. Results Among our sample of 405 youth who had initiated injecting at baseline or during study observation, the median age was 22 years (interquartile range [IQR] = 21 – 24), and 72% (293) reported becoming a regular injector at some point after their first injection experience. Of these, the majority (n=186, 63%) reported doing so within a month of initiating injection drug use. In multivariate analysis, the drug used at the first injection initiation event (opiates vs. cocaine vs. methamphetamine vs. other; all p > 0.05) was not associated with progression; however, younger age at first injection (adjusted odds ratio [AOR] =1.13), a history of childhood physical abuse (AOR =1.81), prior regular use of the drug first injected (AOR =1.77), and having a sexual partner present at the first injection event (AOR =2.65) independently predicted progression to regular injecting. Conclusion These data highlight how quickly youth progress to become regular injectors after experimentation. Findings indicate that addressing childhood trauma and interventions such as evidence-based youth focused addiction treatment that could prevent or delay regular non-injection drug use, may reduce progression to regular injection drug use among this population.Medicine, Faculty ofMedicine, Department ofReviewedFacultyResearcherGraduat