Abstract
BACKGROUND: In April 2020, Japan's revised Health Promotion Act (HPA) banned cigarette smoking and heated tobacco products (HTP) use in indoor public places but exempted small establishments and permitted smoking-designated/HTP-designated rooms. This pre-post study evaluated the effectiveness of the HPA. METHODS: Data were from waves 1 to 4 (2018-2021) of the International Tobacco Control Japan Surveys among a national cohort of adults who smoke cigarettes, use HTPs and do not use any tobacco products. The sample sizes in the respective surveys were 4615, 4222, 4387 and 4254. Multivariable logistic regression models employing generalised estimating equations estimated the prevalence of observed and self-reported indoor smoking/HTP use in key public venues (restaurants/cafés, bars/pubs and workplaces), smoke-free places, and homes, and smoke-free/HTP aerosol-free home policies (model 1). The models were additionally adjusted for waves 1-4 to estimate the impacts of the HPA (model 2). RESULTS: The implementation of the HPA significantly reduced observed indoor smoking in bars/pubs (model 1: 82.2% (pre) to 55.5% (post), model 2: p=0.04) but not in restaurants/cafés (model 1: 53.0%-24.9%, model 2: p=0.15) or workplaces (model 1: 35.3%-30.1%, model 2: p=0.62). Observed indoor HTP use was also common postimplementation (restaurants/cafés: 19.6%, bars/pubs: 53.9%, workplaces: 36.4%). The implementation of the HPA was associated with a significant increase in observed HTP use in smoke-free places (model 1: 26.3%-33.3%, model 2: p=0.001) and a suggestive increase in homes without HTP aerosol-free policies among adults who smoke (model 1: 64.0%-77.0%, model 2: p=0.09). CONCLUSIONS: The implementation of the HPA was limited in its effectiveness. Comprehensive regulations with no exemptions are needed in Japan.