title: Do cigarette warning labels reduce smoking? Paradoxical effects among adolescents.
abstract: OBJECTIVE
  To examine the association between adolescents knowledge of cigarette warning labels and actual smoking behavior.
  
  
  METHODS
  Cohort analytic study.
  
  
  METHODS
  Four public high schools in northern California.
  
  
  METHODS
  Seventeen hundred forty-seven ninth graders (mean age, 14.9 years). Students from 2 of the schools (n = 803) were observed for approximately 3 months.
  
  
  METHODS
  Self-reported knowledge of warning labels was assessed at baseline. Self-reports of smoking behavior were completed at baseline and at follow-up.
  
  
  RESULTS
  Greater knowledge of cigarette package warning labels was significantly associated with higher levels of smoking. Knowledge of warning labels on magazine and billboard advertisements did not differ significantly by level of smoking. In the longitudinal sample, greater knowledge of cigarette package warning labels was significantly associated with a subsequent increase in smoking, controlling for the baseline level of smoking, sex, ethnicity, and knowledge of warning labels on cigarette advertisements (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.02-1.46). Knowledge of warning labels on cigarette advertisements was not associated with a significant change in smoking behavior (OR, 1.06; 95% CI, 0.82-1.35).
  
  
  CONCLUSIONS
  Sizable proportions of adolescent smokers are not seeing, reading, or remembering cigarette warning labels. In addition, knowledge of warning labels on cigarette packages and advertisements is not associated with reduced smoking. The current warning labels are ineffective among adolescents.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Calif, USA.
authors.forename: T N
authors.initials: TN
authors.lastname: Robinson
authors.forename: J D
authors.initials: JD
authors.lastname: Killen
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000329:Advertising; D017007:Duty to Warn; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010947:Plants, Toxic; D011356:Product Labeling; D012189:Retrospective Studies; D000074606:Smoking Prevention; D011795:Surveys and Questionnaires; D014026:Nicotiana