Behavioral Support by Ex-Smoking Peers Using Instant Messaging for Smoking Cessation: A Randomized Controlled Trial

Chest, S0012-3692(25)05172-4. 2025
Guo, Z., Luk, T. T., Weng, X., Wu, Y., Zhao, S., Lai, Y. K., Cheung, D. Y. T., Tong, H. S. C., Lai, V. W. Y., Lam, T. H., & Wang, M. P.*

Abstract

Background: Peer support could be beneficial for smoking cessation. Randomized controlled trial (RCT) evidence is lacking regarding mobile-based behavioral support offered by ex-smoking peers on smoking cessation in community people who smoke.

Research question: Is mobile-based behavioral support provided by ex-smoking peers effective in promoting smoking cessation among community people who smoke?

Study design and methods: An RCT was conducted with people who smoked daily under the Hong Kong Quit-to-Win Contest 2021. All participants received brief smoking cessation advice at baseline. Each participant in the intervention group joined a three-person chat group of instant messaging apps (eg, WhatsApp), which consisted of the person who smoked, a smoking cessation advisor, and a trained ex-smoking peer who had quit smoking for ≥ 1 year. Personalized behavioral support lasted 3 months through the chat group by ex-smoking peers, including experiences of quitting strategies, coping with withdrawal symptoms, use of smoking cessation services, and encouragement. The control group received six smoking cessation text messages and follow-up reminders. The primary outcome was biochemically validated abstinence at 6 months following intervention initiation. Analysis was by intention-to-treat using Poisson regression with robust variance.

Results: From June to September 2021, a total of 1,105 participants were randomly assigned to the intervention (n = 553) and control (n = 552) groups. At 6 months, compared with the control group, the intervention group showed a nonsignificant increase in biochemically validated smoking abstinence (8.9% vs 6.7%; risk ratio [RR], 1.32; 95% CI, 0.88-1.99) and more usage of smoking cessation services (14.5% vs 10.0%; RR, 1.45; 95% CI, 1.05-2.00). In the intervention group, participants who engaged in instant messaging support exhibited much more validated abstinence (22.2% vs 4.9%; RR, 4.52; 95% CI, 2.66-7.68).

Interpretation: Behavioral support by ex-smoking peers via instant messaging was potentially effective and should be improved to increase smoking abstinence.

Clinical trial registration: ClinicalTrials.gov; No.: NCT04909320; URL: www.Clinicaltrials: gov.

Keywords: mobile health; peer support; randomized controlled trial; smoking cessation.

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(*Corresponding Author)