Int. J. Environ. Res. Public Health 2011, 8 1523 A structured questionnaire was used for in-person interviews to obtain information. Subjects were asked about the smoking policies in their venues, that is, whether it prohibited (did not allow smoking at all in dining areas), restricted (allowed smoking in designated sections of dining areas only) or allowed smoking (allowed smoking everywhere in dining areas). Information on subjects’ demographic characteristics, current smoking status (defined by ever smoking during the month before interview) and exposure to SHS at work in the past week was also collected. Six questions were asked to examine subjects’ knowledge of the effects of tobacco smoke on health, specifically, whether smoking is harmful to smokers’ health; whether passive smoking is harmful to nonsmokers’ health; whether passive smoking can cause lung cancer; whether passive smoking can cause heart diseases; whether children with smoking parents are more likely to develop asthma or other respiratory diseases than those with nonsmoking parents; and whether women with smoking husbands are more likely to get lung cancer than those with nonsmoking husbands. Subjects were also asked about their views on smoking bans in public places, including restaurants and bars. Whenever possible, questions were adapted from a validated questionnaire used by an ongoing Chinese national project during the study period, Monitoring Passive Smoking in Public Places in 2007, which was conducted by the Chinese CDC and interviewed subjects from the general population from 32 provinces and municipalities [18]. New questions were also developed for this study to assess whether subjects believed that smoking bans would reduce hospitality revenues, whether they were willing to ban smoking in their own venues, and the reasons for their positions. This study was approved by the Ethics Review Board of the Chinese CDC. All data were analyzed using Stata/IC 10.0 (College Station, TX, USA). Subjects’ exposure to SHS, their knowledge of tobacco smoke and health, their support for smoking bans in restaurants and bars, and the reasons for their unwillingness to ban smoking in their own venues were described. Backward stepwise logistic regression models were used to explore factors that would impact respondents’ attitudes towards smoking bans in restaurants or bars. Explanatory variables including city, type of venue, subjects’ age, gender, education, current smoking status, knowledge on tobacco smoke, and opinions on smoking bans and hospitality revenues. Subjects’ overall knowledge of health effects of tobacco smoke was graded in a 6 point scale, with one point given for each correct answer. Potential interactions effects between gender and smoking status, age and smoking status, smoking status and knowledge scores, and education level and knowledge scores were considered for model developments. Wald tests were used to test restricted versus full models, interaction items and variables with p values of Wald test greater than 0.20 were excluded from the model. 3. Results A total of 814 establishments (665 restaurants and 149 bars) were included in the study, and all these venues’ owners or managers were interviewed. Fifty one percent of the subjects were males, 30% were more than 35 years old, 45% had higher than high school education, and 35% were current smokers (Table 1). Subjects from Wuhan were relatively order and subjects from Guiyang had relatively higher education than those in other cities. No significant differences in other demographic characteristics were observed between subjects from different cities.