title: Age of smoking initiation: implications for quitting.
abstract: OBJECTIVE
  The effect of an early age of smoking initiation on cigarette consumption and on the probability of quitting is analyzed for people aged 21 to 39.
  
  
  METHODS
  The data are from Statistics Canada's 1994/95 National Population Health Survey. The findings in this article are based on 3,449 randomly selected respondents aged 21 to 39 who were or had ever been daily smokers.
  
  
  METHODS
  Logistic regression was used to analyze the association between age of smoking initiation and heavy cigarette consumption (more than 20 a day). Survival analysis techniques were used to study the relationship between age of smoking initiation and smoking cessation for men and women. Cox proportional hazard models were used to control for potential confounding factors such as education, household income, depression, chronic stress, self-esteem, and amount smoked.
  
  
  RESULTS
  Among 21- to 39-year-olds, smoking initiation during early adolescence was associated with greater daily cigarette consumption and a lower cumulative probability of quitting.
authors.affiliation: Health Statistics Division, Statistics Canada, Ottawa.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: W J
authors.initials: WJ
authors.lastname: Millar
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D000328:Adult; D017668:Age of Onset; D002170:Canada / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D016016:Proportional Hazards Models; D012649:Self Concept; D012907:Smoking / Q000453:epidemiology* / Q000523:psychology; D016540:Smoking Cessation; D013315:Stress, Psychological / Q000453:epidemiology