Characteristics of patients with AECOPD by blood eosinophil percentage
| Variables | Overall | Eosinophil percentage | P value | |
| <2% (n=1896) | ≥2% (n=1506) | |||
| Age, years | 71.0 (63.0–78.0) | 72.0 (64.0–79.0) | 70.0 (63.0–77.0) | <0.001 |
| Male, n (%) | 2524 (74.2) | 1353 (71.4) | 1171 (77.8) | <0.001 |
| Smoking status, n (%) | ||||
| Non-smoker | 889 (26.1) | 518 (27.3) | 371 (24.6) | 0.08 |
| Former smoker | 1749 (51.4) | 943 (49.7) | 806 (53.5) | |
| Current smoker | 764 (22.5) | 435 (22.9) | 329 (21.8) | |
| Charlson Comorbidity Index, n (%) | ||||
| 0 | 1442 (42.4) | 742 (39.1) | 700 (46.5) | <0.001 |
| 1 | 1230 (36.2) | 708 (37.3) | 522 (34.7) | |
| 2 | 354 (10.4) | 203 (10.7) | 151 (10.0) | |
| ≥3 | 376 (11.0) | 243 (12.8) | 133 (8.8) | |
| Hypertension, n (%) | 1504 (44.2) | 832 (43.9) | 672 (44.6) | 0.67 |
| Diabetes, n (%) | 525 (15.4) | 315 (16.6) | 210 (14.0) | 0.03 |
| Congestive heart failure, n (%) | 74 (2.0) | 47 (2.3) | 27 (1.6) | 0.16 |
| Hospitalised for AECOPD in previous year, n (%) | ||||
| 0 | 2902 (85.3) | 1582 (83.4) | 1320 (87.6) | 0.001 |
| 1 | 331 (9.7) | 202 (10.6) | 129 (8.6) | |
| ≥2 | 169 (5.0) | 112 (5.9) | 57 (3.8) | |
| White blood cell count, 109/L | 6.8 (5.5–8.8) | 7.6 (5.8–10.0) | 6.2 (5.2–7.6) | <0.001 |
| Corticosteroid use during hospitalisation, n (%) | ||||
| Only inhaled corticosteroid | 2124 (62.4) | 954 (50.3) | 1170 (77.7) | <0.001 |
| Systemic corticosteroid | 1278 (37.6) | 942 (49.7) | 336 (22.3) | |
| Antibiotics use during hospitalisation, n (%) | 3178 (93.4) | 1825 (96.3) | 1353 (89.8) | <0.001 |
AECOPD, acute exacerbation of chronic obstructive pulmonary disease.