title: Tobacco use as a predictor of illicit drug use and drug-related problems in Colombian youth.
abstract: OBJECTIVE
  To examine the extent to which personality and peer factors mediate the relationship between early cigarette use and later illicit drug use, as well as associated drug use problems, in a population of Colombian adolescents.
  
  
  METHODS
  A longitudinal study (2-year interval), using face-to-face structured interviews was begun in 1996 using a community-based sample, randomly selected from census data in three cities in Colombia, South America. The participants were 2837 adolescents with a mean age of 15.0 (SD +/- 1.6) years at time 1 (T1). Males comprised 52% of the sample and 65% resided with two parents. Approximately 78% (N = 2226) completed the second structured interview 2 years later (T2). The main outcome measures were marijuana use, other illicit drug use, and associated drug use problems at T2. Three series of logistic regressions were conducted.
  
  
  RESULTS
  The odds of marijuana use (adjusted odds ratio [AOR] = 1.64-2.01; confidence interval [CI]: 1.11-2.94), other illicit drug use (AOR = 1.77-2.49; CI: 1.03-4.19), and associated drug use problems (AOR = 2.25-3.47; CI: 1.45-5.26) at T2, was increased two- to three-fold among adolescents reporting cigarette use at T1, with control on the demographic, personality, and peer factors, as well as T1 drug use variables.
  
  
  CONCLUSIONS
  Earlier adolescent cigarette smoking was directly associated with later marijuana use, other illicit drug use, and problems with drug use.
authors.affiliation: Department of Pediatrics, Miami Children's Hospital, Miami, Florida 33155-3009, USA. lorena.siqueira@mch.com
authors.forename: Lorena M
authors.initials: LM
authors.lastname: Siqueira
authors.forename: Judith S
authors.initials: JS
authors.lastname: Brook
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D003105:Colombia; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D007407:Interviews as Topic; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*
chemical_list: D013287:Illicit Drugs