Secondhand smoke (SHS) exposure before and after the implementation of the Tobacco Free Cities (TFC) initiative in five Chinese cities: a pooled cross-sectional study.

OBJECTIVES

To assess the levels of secondhand smoke (SHS) exposure before and after the implementation of the Tobacco Free Cities (TFC) initiative.

DESIGN

City-wide representative, cross-sectional surveys (Tobacco Questions for Surveys, TQS) were conducted in each participating city before and after the implementation of TFC.

SETTING

Five large Chinese cities (Chengdu, Chongqing, Wuhan, Xiamen and Xi'an) participated in the TFC initiative.

PARTICIPANTS

A total of 10 184 adults participated in the 2015 TQS survey, and 10 233 adults participated in the 2018 TQS survey, respectively.

INTERVENTIONS

The TFC initiative, which included targeted media campaigns, educational programmes, implementing city-wide smoke-free policies and providing cessation interventions, was implemented in these five cities between 2015 and 2018.

MAIN OUTCOME

Self-reported past 30-day (P30D) SHS exposure in indoor workplaces, restaurants and homes.

DATA ANALYSIS

The pre-TFC and post-TFC SHS exposure levels were compared among all residents and among certain population subgroups. Multivariate logistic regressions were used to estimate the adjusted associations between P30D SHS exposure and individual characteristics.

RESULTS

Across all five cities, the overall rate of self-reported P30D SHS exposure declined in indoor workplaces (from 49.6% (95% CI: 46.4% to 52.8%) to 41.2% (95% CI: 37.7% to 44.7%)), restaurants (from 72.4% (95% CI: 69.8% to 74.9%) to 61.7% (95% CI: 58.7% to 64.7%)) and homes (from 39.8% (95% CI: 36.9% to 42.7%) to 34.7% (95% CI: 31.5% to 37.8%)) from 2015 to 2018. These declines were statistically significant after controlling for individual characteristics. The P30D SHS exposure was associated with sex, age, education level, occupation and current smoking status. The associations varied by venues.

CONCLUSIONS

Our analysis showed that compared with the nationwide SHS exposure levels reported in concurrent national surveys, the declines in P30D SHS exposure in five Chinese cities that implemented the TFC initiative were larger in indoor workplaces and restaurants. Our findings suggest that the TFC initiative was effective in reducing SHS exposure in Chinese cities.