Association of heated tobacco product use with smoking cessation in Chinese cigarette smokers in Hong Kong: a prospective study

Introduction: Heated tobacco products (HTPs) are increasingly popular worldwide, but whether they aid or undermine cigarette abstinence remains uncertain. We examined the predictors of HTP initiation and the prospective association of HTP use with cigarette abstinence in community-based smokers in Hong Kong.

Design: Secondary analysis of a randomised clinical trial aimed to evaluate the effectiveness of brief advice and referral for smoking cessation. The interventions were not related to HTP use.

Participants and settings: 1213 carbon monoxide-verified daily cigarette smokers with intentions to quit or reduce smoking proactively recruited from community sites throughout Hong Kong MAIN EXPOSURE: Current (past 7 day) use of HTP at baseline.

Main outcome: Self-reported 7-day point-prevalence cigarette abstinence at 6 months (exclusive use of HTP permitted).

Results: At baseline, 201 (16.6%) and 60 (4.9%) were ever and current HTP users, respectively. During the 6-month follow-up period, 110 of 1012 (10.9%) never users at baseline initiated HTPs. Younger age and higher education significantly predicted initiation. After adjusting for sociodemographic, smoking-related and quitting-related factors, current HTP use at baseline was not associated with cigarette abstinence at 6 months (adjusted prevalence ratio (aPR) 1.08, 95% CI 0.63 to 1.85). The results were similar in persistent users from baseline to 1-month/3-month follow-up (vs non-users; aPR 1.14, 95% CI 0.57 to 2.29). Use of smoking cessation service between baseline and 3-month follow-up significantly predicted cigarette abstinence (aPR 1.70, 95% CI 1.26 to 2.30).

Conclusion: HTP use was not associated with cigarette abstinence at 6 months in a community-based cohort of smokers with intentions to quit or reduce smoking. Trial registration details ClinicalTrials.gov, NCT03565796.