Behavioral heterogeneity among cigarette and e-cigarette dual-users and associations with future tobacco use: Findings from the Population Assessment of Tobacco and Health Study.

Dual-users of cigarettes and e-cigarettes are commonly treated as a single group. Our study applied a more nuanced classification of this complex behavior to examine its associations with future tobacco use behaviors using data from Waves 1 and 3 of the Population Assessment of Tobacco and Health. Dual-users at Wave 1 (n = 1,665) were categorized into 4 groups based on the frequency with which they used each product (i.e., some days, daily). Analyses identified sociodemographic correlates of group membership and the prevalence of (1) completely switching to e-cigarettes and (2) quitting both products by Wave 3. Dual-users who smoked cigarettes every day and used e-cigarettes some days (69.6%) were the majority and more likely to have lower education (p < .001). Although some day smoking and daily e-cigarette use was the least common category (5.9%), these individuals were most likely to have completely switched to e-cigarettes by Wave 3 (aOR = 6.19, 95% CI = 3.91, 9.79). Dual-users who smoked and used e-cigarettes some days were most likely to have completely quit tobacco by Wave 3 (aOR = 3.98, 95% CI = 2.93, 5.40). In general, dual-users who had higher education or income were more likely to have completely switched to e-cigarettes or quit tobacco use by Wave 3. Adults who concurrently use cigarettes and e-cigarettes exhibit considerable heterogeneity in their use of these tobacco products. Dual-users that are higher on the socioeconomic gradient are more likely to engage in plausibly less harmful dual-use behaviors, which are more strongly associated with harm reduction and cessation behaviors. Future research should consider this variation to more accurately characterize the public health impact of dual-use.