Associations between compliance with very low nicotine content (VLNC) cigarettes, abstinence self-efficacy, and quit outcomes in a pilot smoking cessation trial

Background: Switching to Very Low Nicotine Content (VLNC) cigarettes reduces toxicant exposure and nicotine dependence, and may improve smoking cessation. However, non-compliance with VLNCs is often high, which may reduce their effectiveness. Here, we conducted secondary analyses of a pilot smoking cessation trial utilizing VLNCs to examine associations between pre-cessation VLNC compliance and changes in smoking rate, dependence, and abstinence self-efficacy, as well as quit outcomes. Methods: People who smoke daily (n=35) engaged in a 4-week pre-cessation intervention including VLNCs, transdermal nicotine patch, and behavioral counseling. After quit date, participants received 8 weeks of nicotine replacement therapy and 4 additional behavioral sessions, and were followed for 10 weeks to assess abstinence. Compliance with VLNCs was assessed biweekly during pre-cessation using timeline follow-back. Statistical analyses examined associations between VLNC compliance and a) changes in smoking rate, dependence and abstinence self-efficacy over the course of study cigarette use; and b) time to relapse, controlling for other smoking variables. Results: Greater compliance during the second half of study cigarette use was associated with subsequent improvement in self-efficacy (p<.05). Increased self-efficacy and VLNC compliance both predicted lower likelihood of relapse. Nicotine dependence and cigarettes per day both decreased following study cigarette use, but were unrelated to compliance or relapse. Conclusions: Compliance with VLNCs prior to quitting increased abstinence self-efficacy and predicted better quit outcomes above and beyond baseline smoking characteristics. Although preliminary, these findings suggest that identifying strategies to promote exclusive use of VLNCs during a brief pre-cessation window may be beneficial.