The role of subjective responses in electronic cigarette uptake and substitution in adult smokers.

Background: While a majority of cigarette smokers who use electronic cigarettes (e-cigarettes) choose to continue using cigarettes, completely switching to e-cigarettes is necessary to reduce tobacco-related harm. Whether specific subjective responses to e-cigarettes are associated with extent of smoking reduction and complete switching from cigarettes to e-cigarettes is unclear. This study determined whether initial subjective responses to e-cigarettes related to the successful substitution of e-cigarettes for cigarettes and extent of cigarette and e-cigarette use.

Methods: Adult cigarette smokers (N = 58) uninterested in quitting were asked to completely substitute their cigarettes with an e-cigarette (Vuse Solo) for 8 weeks. At week 1, subjective responses to e-cigarettes were measured using the Product Evaluation Scale and Drug Effects/Liking Survey. A Poisson regression examined whether any of these initial subjective responses were associated with smoke-free days, e-cigarette puffs, and cigarettes smoked between weeks 6 and 8 after adjustment for potential confounders. A logistic regression examined the relationship between subjective measures and exhaled carbon monoxide (CO) verified 7-day abstinence at week 8 after adjustment for potential confounders.

Results: Following Holm's p-value adjustment, e-cigarette liking and desire were associated with increased e-cigarette use (adjusted p < 0.01) and decreased cigarette use (adjusted p < 0.05). Measures of psychological reward and drug liking were associated with 7-day abstinence, however this association was no longer significant following p-value adjustment.

Conclusions: Initial subjective responses were related to cigarette and e-cigarette use at weeks 6-8, but not smoke-free days or CO-verified 7-day abstinence.