title: Two-year trends and predictors of e-cigarette use in 27 European Union member states.
abstract: This study assessed changes in levels of ever use, perceptions of harm from e-cigarettes and sociodemographic correlates of use among European Union (EU) adults during 2012-2014, as well as determinants of current use in 2014.
  
  
  
  We analysed data from the 2012 (n=26 751) and 2014 (n=26 792) waves of the adult Special Eurobarometer for Tobacco survey. Point prevalence of current and ever use was calculated and logistic regression assessed correlates of current use and changes in ever use, and perception of harm. Correlates examined included age, gender, tobacco smoking, education, area of residence, difficulties in paying bills and reasons for trying an e-cigarette.
  
  
  
  The prevalence of ever use of e-cigarettes increased from 7.2% in 2012 to 11.6% in 2014 (adjusted OR (aOR)=1.91). EU-wide coefficient of variation in ever e-cigarette use was 42.1% in 2012 and 33.4% in 2014. The perception that e-cigarettes are harmful increased from 27.1% in 2012 to 51.6% in 2014 (aOR=2.99), but there were major differences in prevalence and trends between member states. Among those who reported that they had ever tried an e-cigarette in the 2014 survey, 15.3% defined themselves as current users. Those who tried an e-cigarette to quit smoking were more likely to be current users (aOR=2.82).
  
  
  
  Ever use of e-cigarettes increased during 2012-2014. People who started using e-cigarettes to quit smoking tobacco were more likely to be current users, but the trends vary by country. These findings underscore the need for more research into factors influencing e-cigarette use and its potential benefits and harms.
authors.affiliation: Department of Primary Care and Public Health, School of Public Health, Imperial College London, London, UK.
authors.forename: Filippos T
authors.initials: FT
authors.lastname: Filippidis
authors.affiliation: Department of Primary Care and Public Health, School of Public Health, Imperial College London, London, UK.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Laverty
authors.affiliation: Department of Ergospirometry and Rehabilitation, Medical School, University of Athens, Athens, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Gerovasili
authors.affiliation: Clinic of Social and Family Medicine, School of Medicine, University of Crete, Heraklion, Greece.
authors.forename: Constantine I
authors.initials: CI
authors.lastname: Vardavas
mesh_terms: D000293:Adolescent; D000328:Adult; D000073865:Cigarette Smoking / Q000453:epidemiology; D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005062:European Union; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010465:Perception; D015995:Prevalence; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Cessation; Electronic nicotine delivery devices; Non-cigarette tobacco products; Public opinion