title: Electronic cigarette use among Korean adolescents: a cross-sectional study of market penetration, dual use, and relationship to quit attempts and former smoking.
abstract: OBJECTIVE
  As elsewhere, in South Korea electronic cigarettes (e-cigarettes) are marketed, in part, as a smoking cessation aid. We assessed the prevalence of e-cigarette use among Korean adolescents and the relationship between e-cigarette use and current (past 30-day) smoking, cigarettes/day, attempts to quit conventional cigarettes, and ceasing to use cigarettes.
  
  
  METHODS
  Data from the 2011 Korean Youth Risk Behavior Web-based Survey of 75,643 students aged 13-18 years were analyzed with logistic regression.
  
  
  RESULTS
  A total of 9.4% (8.0% ever-dual users who were concurrently using e-cigarettes and smoking conventional cigarettes and 1.4% ever-e-cigarette only users) of Korean adolescents have ever used e-cigarettes and 4.7% were current (past 30-day) e-cigarette users (3.6% dual users and 1.1% e-cigarettes only). After adjusting for demographics, current cigarette smokers were much more likely to use e-cigarettes than were nonsmokers. Among current cigarette smokers, those who smoked more frequently were more likely to be current e-cigarette users. The odds of being an e-cigarette user were 1.58 times (95% confidence interval, 1.39-1.79) higher among students who had made an attempt to quit than for those who had not. It was rare for students no longer using cigarettes to be among current e-cigarette users (odds ratio, .10; confidence interval, .09-.12).
  
  
  CONCLUSIONS
  Some Korean adolescents may be responding to advertising claims that e-cigarettes are a cessation aid: those who had made an attempt to quit were more likely to use e-cigarettes but less likely to no longer use cigarettes. E-cigarette use was strongly associated with current and heavier cigarette smoking.
authors.affiliation: Center for Tobacco Control Research and Education, University of California San Francisco, San Francisco, California.
authors.forename: Sungkyu
authors.initials: S
authors.lastname: Lee
authors.affiliation: Center for Tobacco Control Research and Education, University of California San Francisco, San Francisco, California.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Grana
authors.affiliation: Center for Tobacco Control Research and Education, University of California San Francisco, San Francisco, California. Electronic address: glantz@medicine.ucsf.edu.
authors.forename: Stanton A
authors.initials: SA
authors.lastname: Glantz
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D003430:Cross-Sectional Studies; D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005260:Female; D006306:Health Surveys / Q000379:methods / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D040541:Marketing / Q000379:methods* / Q000706:statistics & numerical data; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000379:methods / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires
keywords: Adolescents; Dual use; Electronic cigarettes; Electronic nicotine delivery systems; Smoking; Smoking cessation; Tobacco