E-cigarettes an evidence update A report commissioned by Public Health England

E-cigarettes: an evidence update2. MethodologyFor the present report we have included: (1) a synthesis of recent evidence (publishedsince the two PHE 2014 EC reports) with the earlier evidence in the earlier PHE reportsdrawing on both national and international literature; and (2) where feasible, ananalysis of any relevant national unpublished data available to PHE, KCL and partnerorganisations from England, Great Britain or the UK, including: i) Smoking Toolkit Study(UCL); ii) Action on Smoking and Health (ASH) Smokefree GB (adult and youth)surveys; iii) Internet Cohort GB survey; iv) Smokers’ surveys 2014 commissioned byASH from YouGov; and v) the International Tobacco Control (ITC) policy evaluationproject.For the evidence review (1) above, given the short timeframe for this report, asystematic review of the literature was not possible. However, we followed systematicreview methods where possible and searched PubMed for studies from 2014 onwardsusing the following search terms: (("2014/01/01"[Date - Publication] : "3000"[Date -Publication])) AND ((((((((e-cigarette) OR Electronic cigarettes) OR e-cig*) OR electroniccig*) OR ENDS) OR electronic nicotine delivery systems) OR electronic nicotinedelivery system) OR ((Nicotine) AND Vap*)).The term ENDS was used as some studies have referred to e-cigarettes as ElectronicNicotine Delivery Systems (ENDS). This search returned 3,452 records. The titles of allrecords were screened and 798 articles were identified as potentially relevant to thereport. The full papers of abstracts considered relevant by two reviewers were retrievedand reviewed as identified in Appendix A.We wanted to ensure we included the most up-to-date information on EC use andimpact in England. In order to do this we used routine national data sources to retrievemeasures of EC use prevalence, fires, poisoning and other adverse events. Specificallyfor (2) above, we assessed, in addition to published papers, unpublished nationalsurvey data relevant to this work, identifying where findings are peerreviewed/published. The methods of the surveys that we have accessed are as follows:Smoking Toolkit Study (STS, University College London)The STS consists of monthly cross-sectional household interviews of adults (aged16 and over) in England that has been running since November 2006. Each monthinvolves a new nationally representative sample of about 1,800 respondents. Since2009, all respondents who smoked in the last year have been asked questions on EC;since November 2013 all respondents complete questions on EC. For more information,see www.smokinginengland.info17