Background: Dual use of tobacco and cannabis is increasingly common, but it is unclear how it impacts individuals' interest in or ability to stop smoking. If dual users fail to engage in treatment or have worse treatment outcomes, it would suggest that tobacco treatment programs may need to be tailored to the specific needs of those using cannabis and tobacco. Methods: We conducted an observational study using electronic treatment records from adults (18 years and older) who (a) were enrolled in a regional healthcare system in Washington state, (b) sought tobacco cessation treatment through an insurance-covered quitline from July 2016 to December 2018 and (c) had cannabis use frequency during the period of their quitline enrollment documented in their electronic health record (EHR) (n = 1,390). Treatment engagement was defined by the total number of quitline counseling calls and web-logins completed. Point prevalent self-reported tobacco abstinence was assessed 6 months post-quitline enrollment. Results: Thirty-two percent of participants (n = 441) reported dual use of tobacco and any cannabis during the observation period; 9.4% (n = 130) reported daily cannabis use. Among dual users reporting daily cannabis use, 13.9% had a diagnosed cannabis user disorder in the EHR. Neither engagement with quitline counseling nor long-term tobacco abstinence rates differed between those using tobacco-only and either dual-use group (i.e., persons using any cannabis or daily cannabis). Conclusions: Dual use of tobacco and cannabis is common among smokers seen in primary care and those enrolling in quitline care, but it may not undermine tobacco quitline engagement or smoking cessation. Opportunities exist in the US to leverage quitlines to identify and intervene with dual users of tobacco and cannabis.HIGHLIGHTSTobacco quitline care was equally engaging and effective among tobacco users and dual users of tobacco and cannabisMany daily cannabis users calling tobacco quitlines likely have a cannabis use disorderTobacco quitlines can be leveraged to identify and intervene with dual users of tobacco and cannabis.
Keywords: Smoking cessation; cannabis; dual use; electronic health records; tobacco quitline.