Cannabis Co-Use Makes It Harder to Quit Smoking, But Many Quitline Callers Want Help With Both

Cannabis co-use was reported by 27.2% of quitline callers. Co-users were more likely to be male, younger, and have mental health conditions. After controlling for demographics and cessation services, co-users were significantly less likely to quit smoking at 7 months (23.2% vs 28.9%, p < .001). Among co-users, 42.9% intended to quit cannabis within 30 days.

Analysis of Kick It California (state tobacco quitline) caller data from January 2020 through December 2023 (N=45,151). A subgroup (n=3,545) was randomly sampled for 7-month evaluation. Cessation rates compared between co-users and non-co-users, controlling for demographics and cessation service utilization.

Tobacco quitlines are one of the most widely used cessation resources. Learning that over a quarter of their callers also use cannabis -- and that co-use lowers quit rates -- identifies both a problem and an opportunity. The 43% expressing cannabis quit intentions suggests these callers are open to dual intervention.

As cannabis use increases nationally while cigarette smoking declines, the co-use population represents a growing challenge for tobacco cessation. Quitlines that ignore cannabis co-use may be undermining their own effectiveness for over a quarter of their callers.

Observational data from a single state quitline. Self-reported outcomes may overestimate quit rates. The association between co-use and lower quit rates could reflect shared underlying risk factors rather than a direct effect of cannabis on smoking cessation.