The combined effect of very low nicotine content cigarettes, used as an adjunct to usual Quitline care (nicotine replacement therapy and behavioural support), on smoking cessation: A randomized controlled trial

Aim To determine the combined effect of very low nicotine content (VLNC) cigarettes and usual Quitline care [nicotine replacement therapy (NRT) and behavioural support] on smoking abstinence, in smokers motivated to quit. Design Single-blind, parallel randomized trial. Setting New Zealand. Participants Smokers who called the Quitline for quitting support were randomized to either VLNC cigarettes to use whenever they had an urge to smoke for up to 6 weeks after their quit date, in combination with usual Quitline care (8 weeks of NRT patches and/or gum or lozenges, plus behavioural support) or to usual Quitline care alone. Measurements The primary outcome was 7-day point-prevalence smoking abstinence 6 months after quit day. Secondary outcomes included continuous abstinence, cigarette consumption, withdrawal, self-efficacy, alcohol use, serious adverse events and views on the use of the VLNC cigarettes at 3 and 6 weeks and 3 and 6 months. Findings A total of 1410 participants were randomized (705 in each arm), with a 24% loss to follow-up at 6 months. Participants in the intervention group were more likely to have quit smoking at 6 months compared to the usual care group [7-day point-prevalence abstinence 33 versus 28%, relative risk (RR)=1.18, 95% confidence interval (CI): 1.01, 1.39, P=0.037; continuous abstinence 23 versus 15%, RR=1.50, 95% CI: 1.20, 1.87, P=0.0003]. The median time to relapse in the intervention group was 2 months compared to 2 weeks in the usual care group (P<0.0001). Conclusions Addition of very low nicotine content cigarettes to standard Quitline smoking cessation support may help some smokers to become abstinent.