Objective:
To determine the long-term efficacy of “CureApp Smoking Cessation (CASC)” system when added to usual smoking cessation treatments with pharmacotherapy.

Methods:
A randomized, sham-controlled, open-label, multi- center trial was conducted in Japan. 584 adult smokers (aged 23 to 80 years) intending to quit smoking were recruited from October 2017 to January 2018 and allocated 1:1 to CASC treatment and control-app (CTL) groups. Both groups underwent a 12-week standard smoking cessation program including varenicline or nicotine patch. In addition, the CASC group used the CASC app for 24 weeks, which provided video tutorials, interactive chatting with automated guidance system, digital diary, and a mobile CO checker for daily measurements of exhaled CO. The CTL group used a control-app in which all the potentially effective functions on smoking cessation were removed. The primary outcome was a biochemically validated continuous abstinence rate (CAR) from weeks 9 to 24. The secondary outcomes included CAR from weeks 9 to 52, and 7-day point prevalence abstinence (PPA) at weeks 4, 8, 12, 24, and 52.

Results:
Among all participants, 285 in CASC group and 287 in CTL group (572 in total, of which 74.5% were male) downloaded apps and were included in full analysis set. The primary outcome was significantly higher in the CASC group than in the CTL group (63.9% vs 50.5%; odds ratio [OR] 1.73; 95%CI 1.23-2.42; P=0.001). The results of the CAR from weeks 9 to 52 were comparable (52.3% vs 41.5%; OR 1.55; 95%CI 1.11-2.15; P=0.010). Superiority of the CASC group to the CTL group was also proven in the 7-day PPA at all time points.

Conclusions:
A novel smoking cessation app, CASC, could be a promising tool for smoking cessation treatment.