Table 1.
Demographic and selected variables among the CWP cases and control subjects.
| Variables | CWP (n = 693) | Controls (n = 690) | p | |||
|---|---|---|---|---|---|---|
| N | % | N | % | |||
| Age, Year (mean ± SD) | 68.0 ± 11.1 | 67.1 ± 8.4 | 0.113 | |||
| Exposure years (mean ± SD) | 26.6 ± 9.0 | 27.3 ± 7.8 | 0.107 | |||
| Smoking status | ||||||
| Never | 340 | 49.1 | 359 | 52.0 | 0.270 | |
| Ever | 353 | 50.9 | 331 | 48.0 | ||
| Former | 162 | 23.4 | 91 | 13.2 | ||
| Current | 191 | 27.5 | 240 | 34.8 | ||
| Pack-years smoked | <0.001 | |||||
| 0 | 340 | 49.1 | 359 | 52.0 | ||
| 0–20 | 220 | 31.7 | 130 | 18.9 | ||
| >20 | 133 | 19.2 | 201 | 29.1 | ||
| Work type | 0.534 | |||||
| Tunnel and coal mining | 659 | 95.1 | 648 | 94.0 | ||
| Transport | 16 | 2.3 | 17 | 2.5 | ||
| Others | 18 | 2.6 | 25 | 3.6 | ||
| Stage | ||||||
| I | 415 | 59.9 | ||||
| II | 217 | 31.3 | ||||
| III | 61 | 8.8 | ||||