Tobacco use remains a leading cause of mortality and morbidity on a global scale, with approximately 17% of the world’s population reporting tobacco use according to the World Health Organization.  Tobacco cessation consists of many different clinical and public health approaches, often relying, in part, on the multi-billion-dollar cessation industry.  While many interventions and drug-based treatments are found to be more effective than unassisted quitting, long-term outcomes are bleak due to remarkably high relapse and treatment failure rates.  Cannabis may be concurrently used with tobacco for several different motivations, despite health officials’ rebuttals of claims that cannabis smoking is safer or a potential alternative to traditional smoking.  This longitudinal, international study aims to identify relationships between cannabis and cigarette use as it relates to tobacco cessation outcomes. 

The study analyzes data retrieved from the first two waves of the International Tobacco Control (ITC) Four Country Smoking and Vaping Survey.  These waves occurred in 2016 and 2018 and are comprised of data from population-modelled participant samples in the United States, England, Australia, and Canada.  A total of 12,294 survey responses were retrieved from Wave 1, and 4480 were retrieved from Wave 2 (36% follow up rate).  Response variables of interest were the following: cigarette use frequency, cigarette cessation attempts, cigarette cessation status, cannabis use frequency, and cannabis use methods.  The data was analyzed using covariates and multiple multinomial logistic regressions.   

Results of the data analysis found approximately one-quarter of all smokers also reported past-year cannabis use, with the highest proportion of cannabis users found in Canada (32%).  Primary findings suggest that an increase of cannabis use was associated with significantly lower odds of cigarette cessation compared to non-cannabis users, while maintaining or reducing cannabis use was not associated with greater odds of quitting as compared to non-users.   

Takeaway: increasing or initiating cannabis use in cigarette smokers may be linked with poorer tobacco cessation outcomes.  Cessation interventions must also consider concomitant substance use in their approaches.

Driezen P, Gravely S, Wadsworth E, et al. Increasing cannabis use is associated with poorer cigarette smoking cessation outcomes: Findings from the ITC Four Country Smoking and Vaping Surveys, 2016-2018. Nicotine & Tobacco Research. Published online June 10, 2021:ntab122. doi:10.1093/ntr/ntab122