High-risk behaviors associated with transition from illicit non-injection to injection drug use among adolescent and young adult drug users: A case-control study

Objective: The goal of our study was to elucidate characteristics of persons likely to transition into injection drug use so that an identifiable group with high-risk for blood-borne infection may be targeted for interventions. Methods: An age-matched case-control analysis was performed from a cohort study in Baltimore, 1997-1999, of street-recruited non-injection and injection drug users (IDUs), aged 15-30. Cases were IDUs injecting ≤2 years and controls were age-matched persons who used non-injection heroin, cocaine or crack. At baseline, all were interviewed about prior year-by-year behaviors; analysis using conditional logistic regression was based on information for the year prior to injection onset for the case and the same calendar time for the controls as well as recent behaviors for both groups. Results: Of 270 participants, most were African American (78%), female (61%), and HIV seroprevalence was 7% at baseline. IDUs were significantly more likely than controls to be non-African American (adjusted odds ratio (AOR)=0.09) and report high school dropout (AOR=2.32), early sex-trading (AOR=2.72), and recent violence victimization (AOR=9.28). Conclusion: Given that new injectors are at high-risk for HIV and hepatitis yet difficult to reach for prevention efforts, our data suggest some categories to use to target non-injectors who are likely to transition into injection use.