Stop Smoking Practitioners' understanding of e-cigarettes' use and efficacy with particular reference to vapers' socioeconomic status.

We have undertaken four online surveys of Stop Smoking Service (SSS) practitioners in England, between 2011 and 2016, in order to enhance our understanding of e-cigarettes: a fast moving new phenomenon. It is important to understand whether e-cigarettes can ameliorate or exacerbate health inequalities given that smoking is one of the most serious causes of excessive mortality and morbidity among disadvantaged groups globally. To update findings of previous surveys and examine socioeconomic status differences in e-cigarette use and efficacy. Analysis was undertaken of electronic surveys, particularly, the most recent 2016 survey ( = 514) and 2015/16 SSS client routine monitoring data. SSS practitioners were becoming more positive about e-cigarettes: 42% agreed that e-cigarettes were a good thing compared with 15% in 2011. Reported use of e-cigarettes among SSS clients was low (about 3%) despite higher quit rates (63% of clients reported being quit at four week follow-up, compared with 51% overall). Where socioeconomic differences in e-cigarettes' efficacy for quitting were identified, affluent and working smokers were advantaged. Low use of e-cigarettes by clients and practitioner opinions suggest that further education of SSS staff is needed if they are to adopt the current service recommendations about e-cigarettes.