Table 1.
Study population characteristics of female never-smoking lung cancer cases and population-based controls in Xuanwei and Fuyuan, China
| Characteristic | Cases |
Controls |
p Value | ||
|---|---|---|---|---|---|
| n = 1031 | n = 493 | ||||
|
| |||||
| Age, years, mean, SD | 54.7 | 10.6 | 54.7 | 11.4 | 1.00 |
| County, n, % | |||||
| Xuanwei | 641 | 62.2 | 296 | 60.0 | 0.42 |
| Fuyuan | 390 | 37.8 | 197 | 40.0 | |
| Ever used smoky coal, n, % | |||||
| No | 21 | 2.0 | 59 | 12.0 | 7.0E-151 |
| Yes | 1006 | 97.6 | 432 | 87.6 | |
| Lifetime smoky coal use, tons, mean, SD | 178 | 101 | 148 | 121 | 7.8E-121 |
| Ever exposed to secondhand smoke, n, % | |||||
| No | 41 | 4.0 | 10 | 2.0 | 4.9E-021 |
| Yes | 990 | 96.0 | 483 | 98.0 | |
| Ever used a stove with a chimney (ventilation) | |||||
| No | 100 | 9.7 | 60 | 12.1 | 0.16 |
| Yes | 917 | 88.9 | 431 | 87.4 | |
| Food sufficiency before marriage (socioeconomic status) | |||||
| More than enough | 116 | 11.3 | 30 | 6.1 | 9.5E-031 |
| Just enough | 335 | 32.5 | 158 | 32.0 | |
| Not enough | 574 | 55.7 | 303 | 61.5 | |
| Education, n, % | |||||
| Illiterate/No school | 642 | 62.3 | 286 | 58.0 | 2.3E-031 |
| Attended elementary school | 171 | 16.6 | 117 | 23.7 | |
| Graduated elementary school | 102 | 9.9 | 32 | 6.5 | |
| Attended middle school or higher | 115 | 11.2 | 57 | 11.6 | |
| First degree relative with cancer, n, % | |||||
| No | 821 | 79.6 | 459 | 93.1 | 9.7E-131 |
| Yes | 205 | 19.9 | 32 | 6.5 | |
| History of respiratory disease (asthma, bronchitis, emphysema, tuberculosis), n, % | |||||
| No | 927 | 89.9 | 473 | 95.9 | 5.6E-051 |
| Yes | 104 | 10.1 | 20 | 4.1 | |
1
p-Values <0.05 were considered statistically significant. Continuous variables were compared using Wilcoxon rank sum tests. Categorical variables were compared using Chi-square or Fisher’s Exact tests. Discrepancy in counts due to missing data.