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.