title: E-cigarette use in the past and quitting behavior in the future: a population-based study.
abstract: OBJECTIVE
  We examined whether smokers who used e-cigarettes are more likely to quit after 1 year than smokers who had never used e-cigarettes.
  
  
  METHODS
  We surveyed California smokers (n = 1000) at 2 time points 1 year apart. We conducted logistic regression analyses to determine whether history of e-cigarette use at baseline predicted quitting behavior at follow-up, adjusting for demographics and smoking behavior at baseline. We limited analyses to smokers who reported consistent e-cigarette behavior at baseline and follow-up.
  
  
  RESULTS
  Compared with smokers who never used e-cigarettes, smokers who ever used e-cigarettes were significantly less likely to decrease cigarette consumption (odds ratio [OR] = 0.51; 95% confidence interval [CI] = 0.30, 0.87), and significantly less likely to quit for 30 days or more at follow-up (OR = 0.41; 95% CI = 0.18, 0.93). Ever-users of e-cigarettes were more likely to report a quit attempt, although this was not statistically significant (OR = 1.15; 95% CI = 0.67, 1.97).
  
  
  CONCLUSIONS
  Smokers who have used e-cigarettes may be at increased risk for not being able to quit smoking. These findings, which need to be confirmed by longer-term cohort studies, have important policy and regulation implications regarding the use of e-cigarettes among smokers.
authors.affiliation: Wael K. Al-Delaimy, Eric C. Leas, and David R. Strong are with the Department of Family Medicine and Public Health, University of California, San Diego. Mark G. Myers is with the Psychology Service, Veterans Affairs San Diego Healthcare System, and the Department of Psychiatry, University of California, San Diego. C. Richard Hofstetter is with the Graduate School of Public Health and the Department of Political Science, San Diego State University, San Diego, CA.
authors.forename: Wael K
authors.initials: WK
authors.lastname: Al-Delaimy
authors.forename: Mark G
authors.initials: MG
authors.lastname: Myers
authors.forename: Eric C
authors.initials: EC
authors.lastname: Leas
authors.forename: David R
authors.initials: DR
authors.lastname: Strong
authors.forename: C Richard
authors.initials: CR
authors.lastname: Hofstetter
mesh_terms: D000293:Adolescent; D000328:Adult; D002140:California; D003430:Cross-Sectional Studies; D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012306:Risk; D016540:Smoking Cessation