Mobile chat-based support plus nicotine replacement therapy sampling to promote smoking cessation for community smokers: A randomized controlled trial

Introduction: Mobile instant messaging could deliver real-time, personalized, interactive smoking cessation support. Nicotine replacement therapy (NRT) is effective in increasing quit attempts and abstinence but is underused. We assessed the feasibility of mobile chat-based intervention combined NRT sampling (NRT-S) on abstinence. Methods: In this two-arm, single-blinded, randomized controlled trial, adult (.18 years) daily cigarette smokers were proactively recruited from Hong Kong community settings using efoot-in-the-doorf approach during December 2017 to March 2018. All participants received brief advice on quitting, 1-week of NRT-S, active referral to smoking cessation services, and were individually randomized (1:1) at baseline. The intervention group received two months of chat-based support via instant messaging. The control group received general smoking cessation text messages. The primary outcome was smoking abstinence validated by exhaled carbon monoxide (<4 ppm) and salivary cotinine (<10 ng/mL) at 3 and 6 months using intention-to-treat analysis. Results: A total of 119 participants (80.7% male, 60.5% aged 30.40 years) were randomized and analyzed. Among the 14 and 13 self-reported quitters at 3 and 6 months respectively, only 3 and 1 had biochemical validation. The 3 months validated abstinence rate was 2/62 (intervention) vs 1/57 (control) (AOR=1.07; 95% CI: 0.08.13.65). At 6 months follow-up (68.9% of participants retained), more participants in the intervention group reported quitting (10/62 vs 3/57; AOR=2.83; 95% CI: 0.70.11.30), smoking reduction (20/62 vs 11/57; AOR=1.74; 95% CI: 0.71.4.26), and quit attempts (56/62 vs 44/57; AOR=2.61; 95% CI: 0.88.7.82). Significantly more NRT-S use (39/62 vs 22/57; AOR=2.27; 95% CI: 1.04.4.96) was observed in the intervention group. Participants engaged in mobile chat support (21/62) reported more NRT-S use (76.2% vs 56.1%), although not statistically significant. Conclusions: Mobile chat-based support plus NRT-S was feasible and showed preliminary evidence of increased quitting, smoking reduction, quit attempts, and NRT-S use in proactively recruited community smokers.