Effectiveness of the WeChat-based smoking cessation intervention ('WeChat WeQuit' program) in China: study protocol for a randomized controlled trial

Background and aims: Since its first release in 2011, WeChat (Chinese pinyin: Wei Xin) has been widely used to promote health. As the most popular all-in-one social media application providing free instant messaging, voice, text, pictures, videos and location information exchange via smartphone, WeChat holds promise for delivering smoking cessation services to a large number of people at low unit cost in China, a country with more than 300 million smokers. This protocol is for a study that aims to assess the efficacy of a WeChat-based smoking cessation intervention ('WeChat WeQuit') for treatment-seeking smokers in China.

Design: In this two-arm randomized controlled trial (RCT), the control group will receive only a digital version of a booklet of 'Happy Quit'. The intervention group will also receive the 2 weeks pre- and 12 weeks post-quit 'WeChat WeQuit' intervention. Both groups will be followed-up to 26 weeks (6 months) after quit day.

Setting: This on-line trial has no restrictions on setting or location.

Participants: Chinese-speaking current smokers (have smoked ≥100 cigarettes in their life-time and currently smoke cigarettes) aged 18+ years willing to make a quit attempt within 1 month (n = 2000) will be recruited by on- and off-line advertising. Potential participants will register their interest by sending WeChat messages or text messages, or making a voice call.

Measurements: The primary outcome measure is self-reported 26-week continuous smoking abstinence with biological verification [test by clinic visit: expired carbon monoxide concentration <10 parts per million (p.p.m.) or by mailing cotinine urine dipsticks: urine cotinine <200 ng/ml]. Secondary outcome measures include: 7-day point prevalence abstinence at weeks 1, 4, 8, 12, 16, 20 and 26 after-quit day; self-reported 12-week continuous smoking abstinence and 26-week continuous smoking abstinence; reductions in number of cigarettes smoked per day; and rates of participation in and completion of the smoking-cessation program.

Conclusions: If the 'WeChat WeQuit' program is found to be effective, it will be an accessible, affordable and widely implementable intervention to help cigarette smokers to quit. The potential public health impact of its expansion into underserved regions or communities is considerable.