BMJ Open | 2019
Are ‘dual users’ who smoke and use e-cigarettes interested in using varenicline to stop smoking altogether, and can they benefit from it? A cohort study of UK vapers
Abstract
Objectives Smokers who use e-cigarettes (EC) do so mostly to stop smoking, but many continue to use both products. It is not known whether these ‘dual users’ are interested in stop-smoking medications and whether they can benefit from them. Setting, participants and measures Dual users were recruited over social media and posted study questionnaire and saliva kits at baseline, 3 and 6\u2009months. Those interested in varenicline were posted the medication and received weekly calls over the first 6\u2009weeks, followed by three calls at fortnightly intervals. Results Of 204 participants, 124 (61%, CI=54% to 68%) expressed interest in receiving varenicline and 80 (39%, CI=32% to 45%) started varenicline (varenicline users, VU). VU were more dependent smokers (F=6.2, p=0.01) with higher cigarette consumption (F=8.7, p<0.01) who were using stronger nicotine e-liquids (F=13.9, p<0.001) than dual users not opting for varenicline (varenicline non-users, VN). In terms of abstinence for at least 3\u2009months at the 6-month follow-up, VU were more likely than VN to report abstinence from smoking (17.5% vs 4.8%, p=0.006, RR=3.6, CI:1.4 to 9.0), vaping (12.5% vs 1.6%, p=0.007, RR=7.8, CI:1.7 to 34.5) and both smoking and vaping (8.8% vs 0.8%, p=0.02, RR=10.9, CI:1.4 to 86.6). The differences were significant across sensitivity analyses (RRs=4.9\u2009to 14.0; p=0.02 to p<0.001 at 3\u2009months; RRs=3.0\u2009to 14.0; p=0.01\u2009to p<0.001 at 6\u2009months). VU reported a greater reduction in enjoyment of vaping by the end of the varenicline use period (F=4.1, p=0.04) and recorded a significantly greater reduction in nicotine intake than VN at 3\u2009months (F=13.9, p<0.001) and 6\u2009months (F=26.5, p<0.001). Conclusion Varenicline offered to dual users is likely to promote successful abstinence from both smoking and vaping, although a randomised trial is needed to confirm this. Among dual users who want to stop smoking, there seems to be a high level of interest in smoking-cessation treatments.