“…In the UK, an estimated 2.9 m smokers have quit smoking using e-cigarettes (Action on Smoking and Health ( ASH, 2017 )) and smoking cessation is the most commonly cited reason for use ( Office for National Statistics, 2016 ). E-cigarettes, therefore, have potential to aid smoking cessation and reduce smoking related disease and evidence suggests they are as, or more, effective than NRT ( Brown, Beard, Kotz, Michie, & West, 2014 ; McRobbie, Bullen, Hartmann-Boyce, & Hajek, 2012 ), though there is evidence from England and other EU countries that many smokers who use e-cigarettes also continue to smoke ( West, Beard, & Brown's, 2018 , Smoking Toolkit Study (STS); Farsalinos et al, 2018 ).…”