Voluntary home and car smoke-free rules in Japan: a cross-sectional study in 2015

Objectives: Recently, the Tokyo Metropolitan Assembly passed an ordinance prohibiting smoking in private homes and cars if children are present. However, no previous study has investigated existing, voluntary home and car smoke-free rules in Japan. Therefore, we examined prevalence and determinants of comprehensive home and car smoke-free rules. Design: A cross-sectional study. Setting: Internet survey data with adjustments using inverse probability weighting for ‘being a respondent in an internet survey’. Participants: 5600 respondents aged 15-69 years in 2015 were analyzed to estimate weighted percentages and prevalence ratios (PRs) with 95% confidence intervals (CIs) of having comprehensive home and car smoke-free rules. Main outcome measures: Respondents who answered ‘smoking is never allowed’ in their home or car were defined as having home and car smoke-free rules. Results: Overall, 47.0% (95% CI = 45.8–48.3) of respondents implemented comprehensive home and car smoke-free rules. ...