E-cigarettes and expectancies: why do some users keep smoking?

BACKGROUND AND AIMS Many smokers who have tried electronic cigarettes ('e-cigarettes') continue to smoke, perhaps influenced by their beliefs about the outcomes of using e-cigarettes ('e-cigarette expectancies'). The primary aims of this study were to compare expectancies of dual users to former smokers, and to examine the association between expectancies and intentions to quit or reduce 'vaping' among former smokers. DESIGN AND SETTING A large cross-sectional online survey of e-cigarette users conducted in the United States. PARTICIPANTS We surveyed current e-cigarette users (n = 1815), including both current cigarette smokers ('dual users', n = 381) and former smokers (n = 1434). We further subdivided former smokers into those with (n = 686) and without (n = 748) intentions to reduce or quit e-cigarette use. MEASUREMENTS The primary outcomes were self-reported past-month smoking status and, among former smokers, current intentions to reduce or quit e-cigarette use, both adjusted for potential confounders. E-cigarette expectancy items were derived primarily from a previously validated measure of smoking expectancies. FINDINGS Dual users reported less positive expectancies than former smokers about e-cigarettes, rating e-cigarettes as more physically irritating (β = 0.10, P < 0.001) and addictive (β = 0.06, P = 0.016), as well as less satisfying (β = -0.11, P < 0.001). Former smokers with intentions to quit e-cigarettes also rated e-cigarettes less positively than former smokers without intentions to quit e-cigarettes, rating them more likely to damage health (β = 0.16, P < 0.001) and cause addiction (β = 0.10, P < 0.001), but less likely to taste good (β = -0.08, P = 0.006). CONCLUSIONS Positive e-cigarette expectancies among e-cigarette users are associated with a greater likelihood of having quit smoking, but lower likelihood of intention to quit e-cigarette use.