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

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.

A cross-sectional study.

Internet survey data with adjustments using inverse probability weighting for 'being a respondent in an internet survey'.

5600 respondents aged 15-69 years in 2015 were analysed to estimate weighted percentages and prevalence ratios (PRs) with 95% CIs of having comprehensive home and car smoke-free rules.

Respondents who answered 'smoking is never allowed' in their home and car were defined as having home and car smoke-free rules.

Overall, 47.0% (95% CI=45.8% to 48.3%) of respondents implemented comprehensive home and car smoke-free rules. People who agreed with 'smoking relieves stress' were less likely to have comprehensive smoke-free rules (PR=0.76, 0.71 to 0.82), especially among ever-users of electronic nicotine delivery systems (PR=0.49, 0.30 to 0.81). Higher education was significantly associated with higher PR for comprehensive smoke-free rules (PR=1.30, 1.19 to 1.41). Living with children was significantly associated with higher PR for smoke-free rules among current smokers than not living with children (PR=2.91, 1.99 to 4.27).

In Japan, about 50% of respondents had voluntary smoke-free rules in the home and car. Information on current voluntary smoke-free rules will be useful as baseline information on home and car smoke-free status before enforcement of the 2018 Tokyo home and car smoke-free legislation.