BACKGROUND: Physical exercise is used as a smoking cessation aid but supervised face-to-face exercise trainings reported low attendance and adherence. We evaluated the effectiveness of simple physical exercise practices supported by mobile instant messaging (mHealth) on smoking abstinence.
METHODS: We conducted a 2-arm, parallel, pragmatic cluster randomized controlled trial (cRCT) in 1031 proactively recruited adult daily smokers from 70 community sites across Hong Kong from June to October 2022. The intervention group received brief cessation advice with the use of simple physical exercises (e.g., handgrip and elastic band) and practice reminders via instant messaging for 3 months (n=492). The control group received general brief cessation advice via short message services (n=539). Physical activity level was assessed by International Physical Activity Questionnaire-short form and categorized into low (≤600 metabolic equivalent of task, MET-minutes/week), moderate (600-3,000), and high (≥3,000). The primary outcome was biochemically validated 7-day point prevalence abstinence (PPA) at 3-month after enrolment, analyzed by intention-to-treat. Trial registration: ClinicalTrials.gov, NCT05430451.
RESULTS: Of the 1031 participants (80.9% male, mean age [SD] 18.2 [5.5] years), 62.1% responded at 3-month follow-up. Participants in the intervention and control groups had similar validated abstinence rates (9.3% vs. 9.3%; RR=1.01; 95%CI 0.69-1.48) and self-reported PPA (19.9% vs. 19.0%; RR=1.05; 95%CI 0.82-1.35) at 3-month. Intervention group reported a decreasing trend of the weekly practice of the elastic band (from 10.26mins at 1-month to 2.2mins at 3-month) and handgrip (from 9.43mins to 1.81mins) exercises (Ps<0.001). In those who performed moderate to high physical exercise at 3-month, the intervention group had a higher validated abstinence (vs control, 12.1% vs. 10.4%; RR=1.16; 95%CI 0.69-1.96), though not statistically significant.
CONCLUSIONS: Simple physical exercise practices supported by mHealth were not effective in increasing smoking abstinence. Further studies exploring the experiences and perceptions of the intervention and effective strategies to promote adherence are warranted.