Cannabis Use and Subsequent Cigarette Discontinuation Among US Adults in the Population Assessment of Tobacco and Health Study, Waves 1-5

Introduction: This study examined the association between the current co-use of cannabis and cigarettes in the past 30 days and subsequent cigarette discontinuation (past 30-day point-prevalence abstinence) among U.S. adults with established cigarette use in the Population Assessment of Tobacco and Health (PATH) Study. Additionally, we investigated the impact of co-use on the subsequent discontinuation of all combustible tobacco products. Aims and Methods: A total of 26 381 observations contributed by 8218 adults with established cigarette use (ie, smoked >= 100 cigarettes in their lifetime, and currently smoking cigarettes every day or some days) from waves 1-5 of the PATH Study were included in the analysis. Weighted generalized estimating equations (GEE) models were used to evaluate the association between current co-use at baseline (waves 1-4) with the outcomes assessed at the subsequent wave (cigarette and combustible tobacco discontinuation at waves 2-5). Final models included: Demographic characteristics (age, sex, race and ethnicity, and educational attainment), behavior characteristics (intention to quit, internalizing symptoms, externalizing symptoms, and substance use problems), and wave-pair. Results: Over one-third (35.91%) of the adults currently smoking cigarettes self-reported co-use during the study period. Cannabis use among adults with established cigarette use increased over time. Co-use was associated with decreased odds of cigarette smoking discontinuation at follow-up, after adjusting for covariates (aOR: 0.81; 95% CI: 0.72, 0.93; p = .0018). Similar effect sizes were observed for the discontinuation of all combustible tobacco products (aOR: 0.75; 95% CI: 0.65, 0.86; p < .0001). Conclusions: Cannabis use among adults with established cigarette use was inversely related to subsequent cigarette discontinuation, suggesting that co-use may reduce the likelihood of successful tobacco cessation. Implications: Findings demonstrate that cannabis use may lead to lower odds of discontinuation among adults with established cigarette use; therefore, individuals who co-use cigarettes and cannabis may need additional tobacco cessation support. Notably, this study observed an increase in the co-use of cigarettes and cannabis, emphasizing the need for researchers and public health programs to shift their focus toward understanding and addressing concurrent substance use among adults who smoke cigarettes.