Clinical characteristics by country
| Characteristic | Belgium | France | Germany | The Netherlands | Spain | USA |
| Subjects | 71 | 294 | 431 | 109 | 369 | 229 |
| Age yrs | 66±10.3 | 64±10.6 | 65±9.9 | 64±9.6 | 68±9.0 | 66±8.9 |
| Sex | ||||||
| Male | 46 (65) | 190 (65) | 274 (64) | 67 (61) | 323 (88) | 122 (53) |
| Female | 25 (35) | 104 (35) | 156 (36) | 42 (39) | 46 (12) | 107 (47) |
| Missing | 0 | 0 | 1 | 0 | 0 | 0 |
| Clinician-rated severity | ||||||
| Mild | 17 (24) | 39 (13) | 70 (16) | 14 (13) | 89 (24) | 26 (11) |
| Moderate | 27 (38) | 171 (58) | 215 (50) | 60 (55) | 180 (49) | 95 (42) |
| Severe | 19 (27) | 75 (26) | 114 (26) | 28 (26) | 85 (23) | 80 (35) |
| Very severe | 8 (11) | 9 (3) | 29 (7) | 7 (6) | 14 (4) | 28 (12) |
| Missing | 0 | 0 | 3 (1) | 0 | 1 (0) | 0 |
| FEV1 % pred | 66±17 | 62±20 | 56±20 | 56±17 | 59±20 | 52±19 |
Data are presented as n, n (%) or mean±sd. FEV1: forced expiratory volume in 1 s; % pred: % predicted.