Initial application of a human laboratory model for estimating the motivational substitutability of e-cigarettes for combustible cigarettes.

This pilot study tested a novel human laboratory model for estimating the extent to which electronic cigarettes (e-cigarettes) serve as motivational substitutes for combustible cigarettes. The model assesses 3 parameters of substitutability, including the: (a) increase in motivational reward value of e-cigarettes after tobacco deprivation; (b) reduction in the reward value of combustible cigarettes after e-cigarette administration; and (c) comparability of the withdrawal-suppressing effects of e-cigarettes versus combustible cigarettes. Dual users (daily smokers, vaped 4+ days/week, M age = 35.3) attended 4 visits after 16-h tobacco product abstinence. For 2 visits, participants completed withdrawal measures and a task assessing smoking’s reward value preceded by either: satiation by vaping or sustained tobacco product deprivation. For 2 other visits, participants completed withdrawal measures and a task assessing vaping’s reward value preceded by either: continued deprivation versus satiation by smoking. Tobacco product deprivation (vs. satiation by smoking) increased vaping’s reward value, indicated by nonsignificantly greater likelihood of initiating vaping versus abstaining for money (d = −.26; adjusted p [padj] = .08) and more vaping episodes purchased (β = .22; padj = .08). Satiation by vaping (vs. deprivation) nonsignificantly reduced smoking initiation (d = .46; padj = .09) and significantly decreased number of cigarettes purchased (β = −.29; padj = .04). Relative to deprivation, vaping suppressed withdrawal-related negative affect, smoking and vape urge, and anhedonia (ds ≥ .54). The magnitude of vaping-induced and smoking-induced withdrawal suppression did not significantly differ for all outcomes other than smoking urge, which was more strongly reduced by smoking (d = −1.57) than vaping (d = −.64). Future application and extension of this model may advance tobacco regulatory science and policy addressing e-cigarette use among smokers. (PsycINFO Database Record (c) 2019 APA, all rights reserved)