Using an intersectional framework to explore cannabis and tobacco co-use patterns: Protocol for a descriptive study.

Cannabis and tobacco co-use is an emerging public health concern linked to increased dependence and reduced cessation success for both substances. However, little is known about how co-use patterns vary by product type, motivation, and demographic characteristics. This protocol outlines a cross-sectional study designed to characterize the frequency, type, and context of cannabis and tobacco co-use among U.S. adult tobacco users using an intersectional framework. A national sample of adults who used tobacco in the past 30 days (N = 3777) were recruited via CloudResearch Prime Panels. Participants completed detailed measures of tobacco and cannabis use, co-use behaviors, motivations, expectancies, health behaviors, and sociodemographic factors. This study employs a stratified sampling strategy to ensure representation across diverse geographic regions, racial and ethnic populations, and socioeconomic strata, and integrates robust data validation and quality control protocols. Results will help inform the development of targeted cessation interventions that address co-use, particularly among disproportionately impacted populations. • Captures nuanced patterns of tobacco use, cannabis use, and tobacco and cannabis co-use across multiple product types. • Examines co-use behaviors in relation to sociodemographic and psychosocial factors. • Informs the development of tailored public health messaging and cessation interventions.