title: Trends in injection drug use behaviors over 10 years among street youth.
abstract: OBJECTIVE
  To determine the temporal trends of initiation into injection drug use, current injection, and recent receptive sharing of injection paraphernalia among street youth.
  
  
  METHODS
  Data from two cohort studies conducted between 1995 and 2005 were combined.
  
  
  METHODS
  Recruitment was done on an ongoing basis. Interviews were performed semi-annually. Overall and annual drug injection incidence rates were calculated with the person-time method. Poisson regression was used to assess the predictive power of calendar year on incidence rate. Generalized estimating equations (GEE) were used to assess linear trends in current injection among street youth and in recent receptive sharing of syringe and other injection paraphernalia among current injection drug users.
  
  
  RESULTS
  By 31 March 2005, 1633 subjects had completed 8875 questionnaires. Most subjects were born in Canada (94%), their mean age at entry was 20 years, 68% were boys and almost half (44%) had injected drugs before recruitment. Among 778 never injectors at entry, 130 subjects initiated injection in 1898 person-years of follow-up (incidence rate: 6.8 per 100 person-years). When controlling for age, calendar year was not a significant predictor of incidence rate. Prevalence of current injection was stable (around 30%). Odds of both sharing behaviors decreased by approximately 10% per year.
  
  
  CONCLUSIONS
  In addition to injection paraphernalia sharing reduction efforts, interventions aimed at preventing initiation into injection drug use among high-risk youth are needed.
authors.affiliation: Programmes d'études et de recherche en toxicomanie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 1111 rue Saint-Charles West, Longueuil, Québec, Canada. Elise.Roy@usherbrooke.ca
authors.forename: Elise
authors.initials: E
authors.lastname: Roy
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Boudreau
authors.forename: Pascale
authors.initials: P
authors.lastname: Leclerc
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Boivin
authors.forename: Gaston
authors.initials: G
authors.lastname: Godin
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006301:Health Services Needs and Demand / Q000639:trends; D018453:Homeless Youth / Q000523:psychology / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D016485:Needle Sharing / Q000639:trends; D016017:Odds Ratio; D011446:Prospective Studies; D011792:Quebec; D015819:Substance Abuse, Intravenous / Q000453:epidemiology* / Q000517:prevention & control