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Association between electronic cigarette use and changes in quit attempts, success of quit attempts, use of smoking cessation pharmacotherapy, and use of stop smoking services in England: time series analysis of population trends

BMJ 2016; 354 doi: (Published 13 September 2016) Cite this as: BMJ 2016;354:i4645
  1. Emma Beard, senior research fellow1 2,
  2. Robert West, professor of health psychology2,
  3. Susan Michie, professor of health psychology1,
  4. Jamie Brown, principal research fellow1 2
  1. 1Research Department of Clinical, Educational and Health Psychology, University College London, London WC1E 7HB, UK
  2. 2Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK
  1. Correspondence to: E Beard e.beard{at}
  • Accepted 15 August 2016


Objectives To estimate how far changes in the prevalence of electronic cigarette (e-cigarette) use in England have been associated with changes in quit success, quit attempts, and use of licensed medication and behavioural support in quit attempts.

Design Time series analysis of population trends.

Participants Participants came from the Smoking Toolkit Study, which involves repeated, cross sectional household surveys of individuals aged 16 years and older in England. Data were aggregated on about 1200 smokers quarterly between 2006 and 2015. Monitoring data were also used from the national behavioural support programme; during the study, 8 029 012 quit dates were set with this programme.

Setting England.

Main outcome measures Prevalence of e-cigarette use in current smokers and during a quit attempt were used to predict quit success. Prevalence of e-cigarette use in current smokers was used to predict rate of quit attempts. Percentage of quit attempts involving e-cigarette use was also used to predict quit attempts involving use of prescription treatments, nicotine replacement therapy (NRT) on prescription and bought over the counter, and use of behavioural support. Analyses involved adjustment for a range of potential confounders.

Results The success rate of quit attempts increased by 0.098% (95% confidence interval 0.064 to 0.132; P<0.001) and 0.058% (0.038 to 0.078; P<0.001) for every 1% increase in the prevalence of e-cigarette use by smokers and e-cigarette use during a recent quit attempt, respectively. There was no clear evidence for an association between e-cigarette use and rate of quit attempts (β 0.025; 95% confidence interval −0.035 to 0.085; P=0.41), use of NRT bought over the counter (β 0.006; −0.088 to 0.077; P=0.89), use of prescription treatment (β −0.070; −0.152 to 0.013; P=0.10), or use of behavioural support (β −0.013; −0.102 to 0.077; P=0.78). A negative association was found between e-cigarette use during a recent quit attempt and use of NRT obtained on prescription (β −0.098; −0.189 to −0.007; P=0.04).

Conclusion Changes in prevalence of e-cigarette use in England have been positively associated with the success rates of quit attempts. No clear association has been found between e-cigarette use and the rate of quit attempts or the use of other quitting aids, except for NRT obtained on prescription, where the association has been negative.

Study registration The analysis plan was preregistered (


  • We thank Lisa Szatkowski, University of Nottingham, for providing comments on the manuscript in relation to ARIMAX modelling.

  • Contributors: EB, JB, SM, and RW designed the study. EB wrote the first draft and conducted the analyses. All authors commented on this draft and contributed to the final version. All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. EB is study guarantor.

  • Funding: The Smoking Toolkit Study is currently primarily funded by Cancer Research UK (C1417/A14135; C36048/A11654; C44576/A19501), and has previously also been funded by Pfizer, GlaxoSmithKline, and the Department of Health. JB’s post is funded by a fellowship from the Society for the Study of Addiction, and Cancer Research UK also provide support (C1417/A14135); RW is funded by Cancer Research UK (C1417/A14135). EB is funded by a fellowship from the National Institute for Health Research’s (NIHR) School for Public Health Research (SPHR) (SPHR-SWP-ALC-WP5), and Cancer Research UK also provide support (C1417/A14135). SW is funded by Cancer Research UK (C1417/A14135), and the SPHR (SPHR-SWP-ALC-WP5) also provide support. The SPHR is a partnership between the Universities of Sheffield, Bristol, Cambridge, and Exeter; University College London (UCL); London School for Hygiene and Tropical Medicine; LiLaC collaboration between the Universities of Liverpool and Lancaster and Fuse; and the Centre for Translational Research in Public Health, a collaboration between Newcastle, Durham, Northumbria, Sunderland, and Teesside Universities. The views expressed are those of the authors(s) and not necessarily those of the NHS, NIHR, or Department of Health. No funders had any involvement in the design of the study, the analysis or interpretation of the data, the writing of the report, or the decision to submit the paper for publication.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare that: RW undertakes consultancy and research for and receives travel funds and hospitality from manufacturers of smoking cessation medications but does not, and will not, take funds from e-cigarettes manufacturers or the tobacco industry. RW and SM are advisers to the National Centre for Smoking Cessation and Training. RW’s salary is funded by Cancer Research UK. SM salary is funded by Cancer Research UK and by the SPHR. EB and JB have received unrestricted research funding from Pfizer; EB and JB are funded by CRUK (C1417/A14135); EB is also funded by the SPHR; and JB is also funded by the Society for the Study of Addiction. All authors declare there are no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: Ethical approval for the Smoking Toolkit Study was granted by the UCL ethics committee (ID 0498/001). Ethical approval was not required for use of data from stop smoking services, as the data are publicly available.

  • Data sharing: For access to the Smoking Toolkit Study, please contact RW (robertwest100{at} The R code for this paper is available at; this code is licensed under a Creative Commons Attribution 4.0 International License, and this research paper should be acknowledged when used.

  • The lead author (the manuscript’s guarantor) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been registered and explained.

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