title: Electronic-cigarette use among young people in Wales: evidence from two cross-sectional surveys.
abstract: OBJECTIVE
  To examine the prevalence of electronic(e)-cigarette use, prevalence of e-cigarette and tobacco use by age, and associations of e-cigarette use with sociodemographic characteristics, tobacco and cannabis use among young people in Wales.
  
  
  METHODS
  Data from two nationally-representative cross-sectional surveys undertaken in 2013-2014. Logistic regression analyses, adjusting for school-level clustering, examined sociodemographic characteristics of e-cigarette use, and associations between e-cigarette use and smoking.
  
  
  METHODS
  Primary and secondary schools in Wales.
  
  
  METHODS
  Primary-school children aged 10-11 (n=1601) and secondary-school students aged 11-16 (n=9055).
  
  
  RESULTS
  Primary-school children were more likely to have used e-cigarettes (5.8%) than tobacco (1.6%). Ever use of e-cigarettes remained more prevalent than ever use of tobacco until age 14-15. Overall, 12.3% of secondary-school students (aged 11-16) reported ever using e-cigarettes, with no differences according to gender, ethnicity or family affluence. The percentage of 'never smokers' reporting having used e-cigarettes was 5.3% at age 10-11 to 8.0% at age 15-16. The proportion of children who had ever used an e-cigarette and reported currently smoking increased from 6.9% among 10-11 year olds to 39.2% in 15-16 year olds. Only 1.5% (n=125) of 11-16 year-olds, including 0.3% of never smokers, reported regular e-cigarette use (use at least once a month). Current weekly smokers were 100 times more likely than non-smokers to report regular e-cigarette use (relative risk ratio (RRR=121.15; 95% CI 57.56 to 254.97). Regular e-cigarette use was also more likely among those who had smoked cannabis (RRR 53.03; 95% CI 38.87 to 80.65).
  
  
  CONCLUSIONS
  Many young people (including never-smokers) have tried e-cigarettes. However, regular use is less common, and is associated with tobacco cigarette use. Longitudinal research is needed to understand age-related trajectories of e-cigarette use and to understand the temporal nature of relationships between e-cigarette and tobacco use.
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Graham
authors: G
authors: Moore
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Gillian
authors: G
authors: Hewitt
authors: South East Wales Trials Unit (SEWTU), School of Medicine, Cardiff University, Cardiff, UK.
authors: John
authors: J
authors: Evans
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Hannah J
authors: HJ
authors: Littlecott
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Jo
authors: J
authors: Holliday
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Nilufar
authors: N
authors: Ahmed
authors: MRC/CSO Social & Public Health Sciences Unit, University of Glasgow, Glasgow, UK.
authors: Laurence
authors: L
authors: Moore
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Simon
authors: S
authors: Murphy
authors: Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), School of Social Sciences, Cardiff University, Cardiff, UK.
authors: Adam
authors: A
authors: Fletcher
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology*; D016017:Odds Ratio; D015995:Prevalence; D012574:Schools; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D062789:Tobacco Products / Q000706:statistics & numerical data*; D014852:Wales / Q000453:epidemiology
keywords: PREVENTIVE MEDICINE; PUBLIC HEALTH; Smoking