| Demographic characteristics | Percentage of total (no. of subjects) | Weighted household SHS exposure rate (%) | χ2 Test | p Value |
| Residence: | ||||
| Rural | 46.4% (3781) | 49.3 | 10.0 | 0.002 |
| Urban | 53.6% (4361) | 45.0 | ||
| Province: | ||||
| Sichuan | 31.8% (2586) | 48.5 | 261.8 | <0.001 |
| Jiangxi | 32.9% (2678) | 60.5 | ||
| Henan | 35.3% (2878) | 38.9 | ||
| Gender: | ||||
| Male | 29.0% (2358) | 42.9 | 48.8 | <0.001 |
| Female | 71.0% (5784) | 51.1 | ||
| Age: | ||||
| 18–29 | 11.5% (936) | 50.7 | 39.5 | <0.001 |
| 30–39 | 29.9% (2438) | 49.9 | ||
| 40–49 | 24.0% (1953) | 49.8 | ||
| 50–59 | 21.5% (1752) | 46.2 | ||
| 60–69 | 13.1% (1063) | 35.6 | ||
| Literacy: | ||||
| Illiterate or semi-illiterate | 12.4% (1007) | 51.6 | 11.4 | <0.001 |
| Primary | 27.4% (2230) | 51.4 | ||
| Junior High | 32.9% (2675) | 45.8 | ||
| Senior High | 15.9% (1293) | 48.7 | ||
| Junior College or above | 11.4% (930) | 45.5 | ||
| Occupation: | ||||
| Doctors/teachers | 5.6% (457) | 46.9 | 13.8 | 0.003 |
| Government officials and state institution staff | 6.9% (558) | 38.7 | ||
| Farmers | 43.5% (3537) | 49.6 | ||
| Others | 44.0% (3578) | 47.3 | ||
| Marital status: | ||||
| Married | 90.0% (7311) | 49.8 | 113.4 | <0.001 |
| Divorced/widowed | 5.5% (448) | 19.8 | ||
| Single | 4.5% (362) | 49.1 | ||
| Total | 8142 | 48.3 |
Unknown or missing observations were not taken into the analysis in table 1. Therefore, the total of subjects in every demographic characteristic might not exactly equal 8142 people.