| Correlated factors | Regression coefficient | SEM | Odds ratio (95% CI) | p Value |
| Demographic factors: | ||||
| Region | ||||
| Henan Province | 1.00 (reference) | |||
| Sichuan Province | 0.35 | 0.06 | 1.43 (1.27 to 1.61) | <0.001 |
| Jiangxi Province | 0.71 | 0.06 | 2.04 (1.82 to 2.30) | <0.001 |
| Gender | ||||
| Male | 1.00 (reference) | |||
| Female | 0.69 | 0.05 | 2.00 (1.80 to 2.23) | <0.001 |
| Age | ||||
| 18–29 years old | 1.00 (reference) | |||
| 60–69 years old | −0.24 | 0.08 | 0.79 (0.67 to 0.91) | <0.01 |
| Literacy | ||||
| Illiterate or semi-illiterate | 1.00 (reference) | |||
| High school and above | −0.12 | 0.05 | 0.89 (0.80 to 0.98) | <0.05 |
| Marital status | ||||
| Married | 1.00 (reference) | |||
| Divorced, widowed | −1.19 | 0.13 | 0.30 (0.24 to 0.39) | <0.001 |
| Occupation | ||||
| Doctors/teachers | 1.00 (reference) | |||
| Farmers = 1 | 0.42 | 0.06 | 1.52 (1.34 to 1.72) | <0.001 |
| Others = 1 | 0.18 | 0.07 | 1.91 (1.05 to 1.36) | <0.01 |
| Respondents’ knowledge: | ||||
| Did not correctly answer all the three questions about the knowledge of the harm caused by SHS exposure | 1.00 (reference) | |||
| Correctly answered all the three questions about the knowledge of the harm caused by SHS exposure | 0.13 | 0.06 | 1.14 (1.02 to 1.28) | <0.05 |
| Respondents’ attitudes towards tobacco control: | ||||
| Policy attitude | ||||
| Did not support all three tobacco control polices | 1.00 (reference) | |||
| Supported all the three tobacco control polices | 0.21 | 0.07 | 1.24 (1.08 to 1.42) | <0.01 |
| Household smoking restriction | ||||
| Allow indoor smoking in some or all indoor places | 1.00 (reference) | |||
| Completely forbid indoor smoking | −1.71 | 0.14 | 0.18 (0.14 to 0.24) | <0.001 |
SEM, standard error of the mean.