Efficacy and long-term engagement of a WeChat-integrated modality versus a traditional quitline on smoking cessation in China: a randomised controlled trial

Abstract Background Digital health interventions offer a promising opportunity to innovate traditional cessation services. Multi-component digital approaches show potential for greater effectiveness than traditional methods, though optimal integration strategies and engagement dynamics are still unclear. This study evaluated ‘Way to Quit’ (WQ)—a theory-guided, integrated modality based on WeChat (a popular social media platform)—compared with a quitline, with particular attention to long-term engagement and its impact on abstinence. Methods A two-arm, open-label, randomised controlled trial was conducted in Beijing, China, from December 1, 2022 to June 13, 2024. We recruited adult smokers intending to quit within one month via online advertisements. Participants were randomly assigned (1:1; using various block sizes) to either a multicomponent WeChat-based intervention (WQ)—integrating a mini-programme (application-like service), a chat group (peer support) and an official account (information channel)—or telephone counselling (Quitline), both lasting four weeks (one pre-quit week and three post-quit weeks). All participants received a four-week supply of nicotine gum by mail for on-demand use. Follow-up assessments were completed at one, three, six, and twelve months after the initiation of the intervention via telephone or online. The primary outcome was biochemically verified 7-day point prevalence abstinence (PPA) at one month. Analyses followed a modified intention-to-treat (mITT) approach. Results A total of 460 adult smokers were enrolled and randomised (WQ: n = 230; Quitline: n = 230), with 414 included in the mITT analysis (WQ: 195; Quitline: 219). At one month, biochemically verified 7-day PPA was 41.5% in the WQ group and 27.9% in the Quitline group (RR, 1.49; 95% CI, 1.14–1.95; P = 0.004). Mini-programme engagement peaked initially but declined after three months, from 99.0% in one month to 6.7% in eight months. Greater usage during the first three months was dose-dependently associated with higher long-term abstinence rates (3-, 6-, and 12-month 7-day PPA), with all P trend < 0.001. Conclusions The WQ modality showed superior short-term efficacy compared with the quitline, supporting its potential as an alternative or adjunct to traditional cessation services. Although long-term engagement remained challenging, early engagement intensity within the first three months strongly predicted twelve-month abstinence. Trial registration The trial was preregistered at Chinese Clinical Trial Registry Identifier ( https://www.chictr.org.cn/bin/project/edit?pid=179013 , ID: ChiCTR2200066427). Registration date: December 5, 2022.