title: E-cigarette use in young Swiss men: is vaping an effective way of reducing or quitting smoking?
abstract: OBJECTIVE
  To test longitudinally differences in conventional cigarette use (cigarettes smoked, cessation, quit attempts) between vapers and nonvapers.
  
  
  METHODS
  Fifteen months follow-up of a sample of 5 128 20-year-old Swiss men. The onset of conventional cigarette (CC) use among nonsmokers, and smoking cessation, quit attempts, changes in the number of CCs smoked among smokers at baseline were compared between vapers and nonvapers at follow-up, adjusted for nicotine dependence.
  
  
  RESULTS
  Among baseline nonsmokers, vapers were more likely to start smoking at follow-up than nonvapers (odds ratio [OR] 6.02, 95% confidence interval [CI] 2.81, 12.88 for becoming occasional smokers, and OR = 12.69, 95% CI 4.00, 40.28 for becoming daily smokers). Vapers reported lower smoking cessation rates among occasional smokers at baseline (OR = 0.43 (0.19, 0.96); daily smokers: OR = 0.42 [0.15, 1.18]). Vapers compared with nonvapers were heavier CC users (62.53 vs 18.10 cigarettes per week, p <0.001) and had higher nicotine dependence levels (2.16 vs 0.75, p <0.001) at baseline. The number of CCs smoked increased between baseline and follow-up among occasional smokers (b = 6.06, 95% CI 4.44, 7.68) and decreased among daily smokers (b = -5.03, 95% CI -8.69, -1.38), but there were no differential changes between vapers and nonvapers. Vapers showed more quit attempts at follow-up compared with nonvapers for baseline occasional smokers (incidence rate ratio [IRR] 1.81, 95% CI 1.24, 2.64; daily smokers IRR 1.28, 95% CI 0.95, 1.73).
  
  
  CONCLUSIONS
  We found no beneficial effects of vaping at follow-up for either smoking cessation or smoking reduction.
authors.affiliation: Alcohol Treatment Centre, Lausanne University Hospital CHUV, Lausanne, Switzerland; Addiction Switzerland, Lausanne, Switzerland Centre for Addiction and Mental Health, Toronto, Ontario, Canada; University of the West of England, Bristol, United Kingdom.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gmel
authors.affiliation: Life course and social inequality research centre, University of Lausanne, Lausanne, Switzerland.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Baggio
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, Zurich, Switzerland.
authors.forename: Meichun
authors.initials: M
authors.lastname: Mohler-Kuo
authors.affiliation: Alcohol Treatment Centre, Lausanne University Hospital CHUV, Lausanne, Switzerland.
authors.forename: Jean-Bernard
authors.initials: JB
authors.lastname: Daeppen
authors.affiliation: Alcohol Treatment Centre, Lausanne University Hospital CHUV, Lausanne, Switzerland.
authors.forename: Joseph
authors.initials: J
authors.lastname: Studer
mesh_terms: D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data*; D013557:Switzerland / Q000453:epidemiology; D014029:Tobacco Use Disorder / Q000453:epidemiology*; D055815:Young Adult