title: Comparison of the characteristics of long-term users of electronic cigarettes versus nicotine replacement therapy: A cross-sectional survey of English ex-smokers and current smokers.
abstract: BACKGROUND
  Electronic cigarettes (ECs) and nicotine replacement therapy (NRT) are non-combustible nicotine delivery devices being widely used as a partial or a complete long-term substitute for smoking. Little is known about the characteristics of long-term users, their smoking behaviour, attachment to smoking, experience of nicotine withdrawal symptoms, or their views on these devices. This study aimed to provide preliminary evidence on this and compare users of the different products.
  
  
  METHODS
  UK participants were recruited from four naturally occurring groups of long-term (≥6 months) users of either EC or NRT who had stopped or continued to smoke (N=36 per group, total N=144). Participants completed a questionnaire assessing socio-demographic and smoking characteristics, nicotine withdrawal symptoms, smoker identity and attitudes towards the products they were using.
  
  
  RESULTS
  Adjusting for relevant confounders, EC use was associated with a stronger smoker identity (Wald X(2)(1)=3.9, p=0.048) and greater product endorsement (Wald X(2)(1)=4.6, p=0.024) than NRT use, irrespective of smoking status. Among ex-smokers, EC users reported less severe mood and physical symptoms (Wald X(2)(1)=6.1, p=0.014) and cravings (Wald X(2)(1)=8.5, p=0.003), higher perceived helpfulness of the product (Wald X(2)(1)=4.8, p=0.028) and lower intentions to stop using the product (Wald X(2)(1)=17.6, p<0.001) than NRT users.
  
  
  CONCLUSIONS
  Compared with people who use NRT for at least 6 months, those who use EC over that time period appear to have a stronger smoker identity and like their products more. Among long-term users who have stopped smoking, ECs are perceived as more helpful than NRT, appear more effective in controlling withdrawal symptoms and continued use may be more likely.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Nelson
authors.affiliation: Department of Health Behavior, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: Maciej L
authors.initials: ML
authors.lastname: Goniewicz
authors.affiliation: Department of Clinical, Educational and Health Psychology, University College London, London, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Beard
authors.affiliation: Department of Clinical, Educational and Health Psychology, University College London, London, UK.
authors.forename: Jamie
authors.initials: J
authors.lastname: Brown
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Sheals
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: West
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK. Electronic address: lion.shahab@ucl.ac.uk.
authors.forename: Lion
authors.initials: L
authors.lastname: Shahab
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D066300:Electronic Nicotine Delivery Systems / Q000523:psychology*; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000627:therapeutic use*; D017060:Patient Satisfaction; D012647:Self-Assessment; D016540:Smoking Cessation / Q000523:psychology* / Q000706:statistics & numerical data*; D013375:Substance Withdrawal Syndrome / Q000523:psychology; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000188:drug therapy / Q000523:psychology* / Q000628:therapy*; D055815:Young Adult
chemical_list: D009538:Nicotine
keywords: Electronic cigarettes; Harm reduction; Identity; NRT use; Nicotine withdrawal; Smoking cessation