COPD and pneumoconiosis | Pneumoconiosis alone | P value | |
n | 221 | 454 | |
Age, years | 56.0 (51.0–63.5) | 55.0 (48.0–65.3) | 0.086 |
Male | 177 (80.1) | 346 (76.2) | 0.258 |
Smoking exposure, pack-years | |||
0 | 86 (38.9) | 204 (44.9) | 0.002 |
1–9 | 33 (14.9) | 103 (22.7) | |
10–19 | 34 (15.4) | 60 (13.2) | |
≥20 | 68 (30.8) | 87 (19.2) | |
Cumulative pack-years | 20.0 (10.0–30.0) | 10.9 (4.0–22.5) | <0.001 |
BMI, kg/m2 | 24.7 (22.2–26.7) | 25.1 (23.3–27.9) | 0.001 |
Duration of exposure, years | 13.0 (7.0–20.0) | 11.0 (6.0–19.0) | 0.068 |
Latency period, years | 25.0 (14.0–33.0) | 26.0 (12.0–39.0) | 0.320 |
Stage of pneumoconiosis | <0.001 | ||
Ⅰ | 67 (30.3) | 265 (58.3) | |
Ⅱ | 42 (19.0) | 122 (26.9) | |
Ⅲ | 112 (50.7) | 67 (14.8) | |
Exposure dust | <0.001 | ||
Asbestos | 23 (10.4) | 107 (23.6) | |
Silica | 84 (38.0) | 126 (27.8) | |
Coal | 100 (45.2) | 159 (35.0) | |
Other dust | 14 (6.3) | 62 (13.7) | |
Symptoms | |||
Cough | 171 (77.4) | 329 (72.5) | 0.172 |
Sputum production | 123 (55.7) | 219 (48.2) | 0.070 |
Dyspnoea | 129 (58.4) | 264 (58.1) | 0.956 |
Data was presented as n (%) or median (IQR).
BMI, body mass index; COPD, chronic obstructive pulmonary disease.