Background:
Secondhand smoke (SHS) poses a major public health threat in China, causing over 100,000 deaths/year. China, however, has not yet implemented a national comprehensive smoke-free law, and the few subnational laws are only partial. This study presents trends in selected cities from 2007 to 2015 in: (1) exposure to SHS in key public places (workplaces, restaurants, bars), and (2) smokers' support for comprehensive smoke-free laws, comparing cities and rural areas in 2013-15.

Methods:
Data are from Waves 2 to 5 of the International Tobacco Control (ITC) China Survey (2007-15), a face-to-face cohort survey of 800 smokers in each of five cities (Beijing, Guangzhou, Kunming, Shanghai, Shenyang), plus five rural areas at Wave 5 (2013-15) (total N=8000). GEE logistic regression models tested changes over time.

Results:
At the latest wave (2013-15), the majority of respondents reported being exposed to SHS in public places. Smoking was most prevalent in bars, with little reduction over time across cities (from 93% overall in 2007 to 86% in 2013-15). Smoking in other venues decreased over time, but remained very high in 2013-15 (from 94% to 67% for restaurants; and 75% to 51% for workplaces). In rural areas, smoking prevalence was higher in workplaces (73% vs 56%, p< .001) and lower in bars (73% vs 88%, p< .05) compared to cities; there was no difference in restaurants. Support for complete smoking bans among smokers in cities increased over time for each venue and is higher than nearly all other 20+ ITC countries. Support did not differ between cities and rural locations.

Conclusions:
Partial smoke-free laws in China are failing to protect both urban and rural residents from SHS, demonstrating the urgent need for a comprehensive national smoke-free law, as called for by the FCTC. Such a law would be supported by the majority of the Chinese public.