%0 Journal Article %A Kaitlyn M Berry %A Lindsay M Reynolds %A Jason M Collins %A Michael B Siegel %A Jessica L Fetterman %A Naomi M Hamburg %A Aruni Bhatnagar %A Emelia J Benjamin %A Andrew Stokes %T E-cigarette initiation and associated changes in smoking cessation and reduction: the Population Assessment of Tobacco and Health Study, 2013–2015 %D 2018 %R 10.1136/tobaccocontrol-2017-054108 %J Tobacco Control %P tobaccocontrol-2017-054108 %X Background The role of electronic cigarettes (e-cigarettes) in product transitions has been debated.Methods We used nationally representative data from the Population Assessment of Tobacco and Health Study waves 1 (2013–2014) and 2 (2014–2015) to investigate the associations between e-cigarette initiation and cigarette cessation/reduction in the USA. We limited the sample to current cigarette smokers aged 25+ years who were not current e-cigarette users at wave 1. We modelled 30-day cigarette cessation and substantial reduction in cigarette consumption as a function of e-cigarette initiation between surveys using multivariable logistic regression.Results Between waves 1 and 2, 6.9% of cigarette smokers who were not current e-cigarette users transitioned to former smokers. After adjusting for covariates, cigarette smokers who initiated e-cigarette use between waves and reported they used e-cigarettes daily at wave 2 had 7.88 (95% CI 4.45 to 13.95) times the odds of 30-day cigarette cessation compared with non-users of e-cigarettes at wave 2. Cigarette smokers who began using e-cigarettes every day and did not achieve cessation had 5.70 (95% CI 3.47 to 9.35) times the odds of reducing their average daily cigarette use by at least 50% between waves 1 and 2 compared with e-cigarette non-users.Conclusions Daily e-cigarette initiators were more likely to have quit smoking cigarettes or reduced use compared with non-users. However, less frequent e-cigarette use was not associated with cigarette cessation/reduction. These results suggest incorporating frequency of e-cigarette use is important for developing a more thorough understanding of the association between e-cigarette use and cigarette cessation. %U https://tobaccocontrol.bmj.com/content/tobaccocontrol/early/2018/03/24/tobaccocontrol-2017-054108.full.pdf