Main clinical characteristics of the population studied
| ECOPD patients | Control patients | p-value | ICSs | No ICSs | p-value | |
| Subjects | 318 | 674 | 576 | 416 | ||
| Age years | 71.4±11 | 70.2±13 | 0.155 | 71.9±10 | 72.8±9 | 0.145 |
| Male | 208 (65) | 425 (63) | 0.541 | 372 (64.6) | 275 (66.1) | 0.625 |
| BMI kg·m−2 | 28.5±6.6 | 28.2±7 | 0.393 | 28.6±6.5 | 28.4±7.2 | 0.648 |
| Pack-years (median) | 50 | 51 | 0.194 | 53 | 50 | 0.131 |
| FEV1 % pred | 49±18 | 64.5±19 | <0.0001 | 47.3±18 | 56.6±19 | <0.0001 |
| ICS | 253 (79) | 323 (47.9) | <0.0001 |
Data are presented as n, mean±sd or n (%), unless otherwise stated. ECOPD: exacerbations of chronic obstructive pulmonary disease; ICS: inhaled corticosteroid; BMI: body mass index; FEV1: forced expiratory volume in 1 s.