Table 1 Baseline characteristics of the study population according to disease status
Variables | Groups | pValue | |
|---|---|---|---|
| Â | COPD (n = 1100) | Controls (n = 1100) | Â |
Number (Percentage, %) | |||
Female sex | 273 (24.8) | 273 (24.8) | ≥0.05 |
Educated level to high school or beyond | 21 (1.9) | 21 (1.9) | ≥0.05 |
Smoking history | |||
Past smoker | 264 (24.0) | 12 (1.1) | <0.05 |
Current smoker | 226 (20.5) | 235 (21.4) | Â |
Never smoker | 610 (55.5) | 853 (77.5) | Â |
HADS-A ≥ 8 | 201 (18.3) | 58 (5.3) | <0.05 |
HADS-D ≥ 8 | 393 (35.7) | 79 (7.2) | <0.05 |
Mean (SD) or median (quartile) | |||
Age | 63.2 (40–75) | 62.1 (39–76) | ≥0.05 |
Average number of family members | 2.86 (1–4) | 2.86 (1–4) | ≥0.05 |
Annual net income per family (yuan) | 17002 (440) | 17477 (469) | <0.05 |
BMI (kg/m2) | 23.3 (2.8) | 23.4 (3.0) | ≥0.05 |
FEV1(L) | 1.27 (0.36) | 2.55 (0.68) | <0.05 |
FEV1, % of predicted value | 45.2 (10.8) | 88.6 (9.2) | <0.05 |
FEV1/FVC | 47.9 (11.5) | 83.6 (9.3) | <0.05 |
6MWD (m) | 445.0 (91.0) | 580.1 (99.8) | <0.05 |
HADS-A score | 4.8 (2.3) | 3.1 (1.6) | <0.05 |
HADS-D score | 5.4 (2.6) | 3.5 (2.4) | <0.05 |