title: Prevalence and temporal trends of crack injection among injection drug users in eastern central Canada.
abstract: BACKGROUND
  Little is known about crack injection and its temporal trends in North America. This article describes the extent of crack injection and examines temporal trends among injection drug users (IDUs) recruited from 2003 to 2010 in the SurvUDI network.
  
  
  METHODS
  IDUs who injected recently (past 6 months) were recruited in harm reduction and health programs in eastern central Canada. Trend analyses were performed using generalized estimating equations. Some IDUs participated multiple times; first interview was retained for the descriptive analyses, while first interview per year was retained for the trend analyses.
  
  
  RESULTS
  Of the 4088 IDUs recruited, 15.2% (621) reported crack injection; large variations across sites were noted (range: 0.3-39.5%). Trend analyses were limited to Ottawa (449 crack injectors) and Montréal (121). For Ottawa, a significant decline was observed, from 48.3% to 36.9%, with a prevalence ratio (PR) of 0.97 per year (95% CI: 0.94-0.99). For Montréal, a significant rise was observed, from 6.0% to 18.4%, with a PR of 1.29 per year (95% CI: 1.19-1.40).
  
  
  CONCLUSIONS
  Strong variations in crack injection exist throughout the SurvUDI network, and reversed temporal trends have been observed in Ottawa and Montréal. These data will be useful to local harm reduction programs to evaluate the need to distribute items required by crack injectors and to develop prevention messages.
authors.affiliation: Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Chaire de Toxicomanie, Longueuil, Québec J4K 0A8, Canada; Agence de la Santé et des Services Sociaux de Montréal, Direction de Santé Publique, Montréal, Québec H2L 1M3, Canada; Institut National de Santé Publique, Montréal, Québec G1V 5B3, Canada. Electronic address: elise.roy@USherbrooke.ca.
authors.forename: Elise
authors.initials: E
authors.lastname: Roy
authors.forename: Pascale
authors.initials: P
authors.lastname: Leclerc
authors.forename: Carole
authors.initials: C
authors.lastname: Morissette
authors.forename: Nelson
authors.initials: N
authors.lastname: Arruda
authors.forename: Caty
authors.initials: C
authors.lastname: Blanchette
authors.forename: Karine
authors.initials: K
authors.lastname: Blouin
authors.forename: Michel
authors.initials: M
authors.lastname: Alary
mesh_terms: D000328:Adult; D002170:Canada / Q000453:epidemiology; D019970:Cocaine-Related Disorders / Q000453:epidemiology*; D016578:Crack Cocaine / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D015995:Prevalence; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D013997:Time Factors
chemical_list: D016578:Crack Cocaine
keywords: Crack injection; Crack-cocaine; Injection drug use; Temporal trends