Table 1.
Characteristics of controls and cases in a Chinese Han population.
| Variable | Control | Case | p Valueb |
|---|---|---|---|
| Total | 318 | 301 | |
| Age (mean ± SD, years) | 56.1 ± 12.0 (19–75) | 59.6 ± 10.8 (23–84) | 0.002 |
|
| |||
| Gender | 0.956 | ||
|
| |||
| Male, n (%) | 156 (49%) | 147 (49%) | |
| Female, n (%) | 162 (51%) | 154 (51%) | |
|
| |||
| Smoking status | 0.974 | ||
|
| |||
| Nonsmokers | 231 (73%) | 219 (73%) | |
| Smokers | 87 (27%) | 82 (27%) | |
|
| |||
| TNMa | |||
|
| |||
| I + II | 183 (61%) | ||
| III + IV | 118 (39%) | ||
a
Tumor, node, metastasis;
b
t-Tests and chi-square tests were used to test for difference between cases and controls.