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

E-cigarettes: an evidence updatesmoking cessation (30-day abstinence) in a sample of smokers enrolled in a web-basedcessation programme in the US with three-month follow-up. Pearson illustrated how therelation between using EC to quit and successful smoking cessation depended on thefactors that were adjusted for and how the data were analysed, finding that under someconditions EC use was related to being less likely to quit and in others there was norelationship. The authors concluded that caution needs to be exerted when interpretingobservational studies of the effects of EC use on smoking cessation.Borderud et al., 2014 [52] examined whether any use of EC in the past 30 days wasrelated to smoking cessation outcomes in a group of cancer patients enrolled in asmoking cessation programme in the US. When treating all smokers who dropped out ofthe study as smoking cessation failures, the authors found that any use of EC in the last30 days was related to being less likely to quit; however, this treatment of the data mayhave been problematic because more EC users than non-users dropped out of thestudy. No relationship between EC use in the last 30 days and smoking cessation wasobserved when drop-outs were excluded from the analyses. One potential problem withthis study is the measure of any EC use in the last 30 days, as this could range fromusing an EC once in the last 30 days to using an EC daily for the past 30 days. Asillustrated [16, 44, 45] and discussed in previous studies [51], measurements of EC usethat do not fully capture frequency of use may influence the relation between EC useand smoking cessation. As with studies in the previous section, the Borderud studystarted with smokers who had tried EC but did not stop smoking. This, of course,seriously reduces the chance of detecting a positive effect.Summary of findingsRecent studies support the Cochrane Review findings that EC can help people to quitsmoking and reduce their cigarette consumption. There is also evidence that EC canencourage quitting or cigarette consumption reduction even among those not intendingto quit or rejecting other support. It is not known whether current EC products are moreor less effective than licensed stop-smoking medications, but they are much morepopular, thereby providing an opportunity to expand the number of smokers stoppingsuccessfully. Some English stop smoking services and practitioners support the use ofEC in quit attempts and provide behavioural support for EC users trying to quit smoking;self-reported quit rates are at least comparable to other treatments. The evidence onEC used alongside smoking on subsequent quitting of smoking is mixed.Policy implicationsoSmokers who have tried other methods of quitting without success could beencouraged to try EC to stop smoking and stop smoking services should supportsmokers using EC to quit by offering them behavioural support.51