Pulmonary function characteristics of patients with or without an obstructive component
| Obstruction | No obstruction | Overall | |
| Patients | 27 (61) | 17 (39) | 44 |
| Severity of disease graded by FEV1 (n=44) | |||
| ≥70% predicted | 3 (11) | 5 (29) | 8 (18) |
| 60–69% predicted | 2 (7) | 5 (29) | 7 (16) |
| 50–59% predicted | 8 (30) | 3 (18) | 11 (25) |
| 35–49% predicted | 7 (26) | 4 (24) | 11 (25) |
| <35% predicted | 7 (26) | 0 (0) | 7 (16) |
| Bronchodilator responsiveness when tested (n=37) | |||
| Present | 12 (52) | 1 (7) | 13 (35) |
| Absent | 11 (48) | 13 (93) | 24 (65) |
| Air trapping among patients with RV measurement (n=43) | |||
| Present | 22 (85) | 2 (12) | 24 (56) |
| Absent | 4 (15) | 15 (88) | 19 (44) |
| DLCO (n=44) | |||
| Reduced DLCO | 13 (48) | 8 (47) | 21 (48) |
| DLCO % predicted median (interquartile range) | 77 (66–86) | 77 (65–99) | 76 (65–92) |
Data are presented as n (%) unless otherwise stated. FEV1: forced expiratory volume in 1 s; RV: residual volume; DLCO: diffusing capacity of carbon monoxide.