[Current status and intention to change indoor smoking rules by enforcing smoke-free legislation in Japan]

Objective　In Japan, the revised Health Promotion Act and the Tokyo Metropolitan Ordinance to Prevent Exposure to Second-hand Smoke have been in place since April 1, 2020. However, regional differences in the prohibition of smoking in restaurants have raised concerns that some restaurants are not regulated by the smoke-free legislation. In addition, outdoor smoking rules have been in place in municipalities prior to the smoke-free legislation, so smoking outside restaurants may occur, and this may obstruct progress in the prohibition of smoking. In this study, we examined the indoor smoking rules before and after the enforcement of the smoke-free legislation, as well as what influenced the changes in these rules.Methods　We conducted a self-administered questionnaire survey in 6,000 restaurants in Tokyo, Osaka, and Aomori prefectures from February to March 2020. We examined the indoor smoking rules before and after the enforcement of the smoke-free legislation and calculated the proportion of change by categorizing the indoor smoking rules into "smoking prohibited," "smoking permitted in separate area," and "smoking permitted."Results　Of the 879 restaurants that responded, 603 indicated that they were not regulated by the smoke-free legislations. The percentage of restaurants that switched from "smoking permitted in separate area" and "smoking permitted" to "smoking prohibited" was 5.2% (3/58) in Tokyo, 23.1% (31/134) in Osaka, and 17.2% (57/326) in Aomori. In addition, when we included restaurants that were already "smoking prohibited" before the enforcement and did not plan to change the rules after the enforcement, the percentage was 46.6% (55/118) in Tokyo, 49.6% (113/228) in Osaka, and 48.6% (125/257) in Aomori.Conclusion　In total, 17.6% (91/518) of the restaurants that were not regulated by the smoke-free legislations would plan to change their indoor smoking rules from "smoking permitted in separate area" and "smoking permitted" to "smoking prohibited." There is a concern regarding the reduction in customers and sales due to the prohibition of smoking, and the existence of outdoor smoking rules prior to the smoke-free legislation may obstruct progress in the prohibition of smoking. It will be important to examine changes in the number of customers and sales resulting from changes to the indoor smoking rules to deal with smokers when smoking is prohibited, and to improve environments set as public smoking spaces in Japan.