title: Electronic cigarettes and conventional cigarette use among U.S. adolescents: a cross-sectional study.
abstract: OBJECTIVE
  To examine e-cigarette use and conventional cigarette smoking.
  
  
  METHODS
  Cross-sectional analyses of survey data from a representative sample of US middle and high school students in 2011 (n = 17 353) and 2012 (n = 22 529) who completed the 2011 and 2012 National Youth Tobacco Survey.
  
  
  METHODS
  Ever and current e-cigarette use.
  
  
  METHODS
  Experimentation with, ever, and current smoking, and smoking abstinence.
  
  
  RESULTS
  Among cigarette experimenters (1 puff), ever e-cigarette use was associated with higher odds of ever smoking cigarettes (100 cigarettes; odds ratio [OR] = 6.31; 95% CI, 5.39-7.39) and current cigarette smoking (OR = 5.96; 95% CI, 5.67-6.27). Current e-cigarette use was positively associated with ever smoking cigarettes (OR = 7.42; 95% CI, 5.63-9.79) and current cigarette smoking (OR = 7.88; 95% CI, 6.01-10.32). In 2011, current cigarette smokers who had ever used e-cigarettes were more likely to intend to quit smoking within the next year (OR = 1.53; 95% CI, 1.03-2.28). Among experimenters with conventional cigarettes, ever use of e-cigarettes was associated with lower 30-day (OR = 0.24; 95% CI, 0.21-0.28), 6-month (OR = 0.24; 95% CI, 0.21-0.28), and 1-year (OR = 0.25; 95% CI, 0.21-0.30) abstinence from cigarettes. Current e-cigarette use was also associated with lower 30-day (OR = 0.11; 95% CI, 0.08-0.15), 6-month (OR = 0.11; 95% CI, 0.08-0.15), and 1-year (OR = 0.12; 95% CI, 0.07-0.18) abstinence. Among ever smokers of cigarettes (100 cigarettes), ever e-cigarette use was negatively associated with 30-day (OR = 0.61; 95% CI, 0.42-0.89), 6-month (OR = 0.53; 95% CI, 0.33-0.83), and 1-year (OR = 0.32; 95% CI, 0.18-0.56) abstinence from conventional cigarettes. Current e-cigarette use was also negatively associated with 30-day (OR = 0.35; 95% CI, 0.18-0.69), 6-month (OR = 0.30; 95% CI, 0.13-0.68), and 1-year (OR = 0.34; 95% CI, 0.13-0.87) abstinence.
  
  
  CONCLUSIONS
  Use of e-cigarettes was associated with higher odds of ever or current cigarette smoking, higher odds of established smoking, higher odds of planning to quit smoking among current smokers, and, among experimenters, lower odds of abstinence from conventional cigarettes. Use of e-cigarettes does not discourage, and may encourage, conventional cigarette use among U.S. adolescents.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Dutra
authors.forename: Stanton A
authors.initials: SA
authors.lastname: Glantz
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D055615:Electrical Equipment and Supplies / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data*; D062789:Tobacco Products / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology