title: Factors associated with adolescent initiation of injection drug use.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the extent to which demographic, sexual, and non-injection drug use practices predict adolescent initiation of injection drug use.
  
  
  METHODS
  Street recruited injection drug users 15-30 years of age in Baltimore, Maryland, who initiated injection within five years of study enrollment, completed a questionnaire that included a year-by-year history regarding the five years prior to initiation of injection. Factors associated with initiation during adolescence (< or = 21 years of age) versus young adulthood (>21 ) were determined using logistic regression.
  
  
  RESULTS
  Of 226 participants, most were female (61%) and African American (64%). Median age of participants was 25; median age at initiation of injection was 23. Factors significantly associated with adolescent initiation in multivariate analysis included race other than African American, and practices prior to initiating injection including condom use, lack of cocaine use, exclusive crack smoking just prior to initiation, and smoking marijuana. Adolescent initiates also had shorter durations of illicit drug use prior to initiating injection.
  
  
  CONCLUSIONS
  Short-term non-injection drug use, particularly exclusive crack smoking, was associated with adolescent initiation of injection drug use. Early prevention efforts targeting this high-risk group of younger drug users are warranted in order to delay or prevent onset of injection drug use.
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA. cf317@columbia.edu
authors.forename: C M
authors.initials: CM
authors.lastname: Fuller
authors.forename: D
authors.initials: D
authors.lastname: Vlahov
authors.forename: A M
authors.initials: AM
authors.lastname: Arria
authors.forename: D C
authors.initials: DC
authors.lastname: Ompad
authors.forename: R
authors.initials: R
authors.lastname: Garfein
authors.forename: S A
authors.initials: SA
authors.lastname: Strathdee
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology / Q000523:psychology*; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000367:Age Factors; D015142:Baltimore / Q000453:epidemiology; D003159:Community-Institutional Relations; D005260:Female; D015658:HIV Infections / Q000209:etiology; D015438:Health Behavior / Q000208:ethnology; D006526:Hepatitis C / Q000209:etiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D011322:Primary Prevention; D011446:Prospective Studies; D018570:Risk Assessment; D012309:Risk-Taking; D012725:Sexual Behavior / Q000208:ethnology; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology* / Q000523:psychology