Pre-bronchodilator iPFT results
| Responders | Non-responders | p-value | |
| Subjects, n | 59 | 34 | |
| Phenotype | |||
| Obstructive | 34 (58%) | 13 (38%) | 0.087 |
| Restrictive | 2 (3%) | 6 (18%) | 0.048 |
| Mixed | 23 (39%) | 15 (44%) | 0.67 |
| Moderate/severe obstruction | 53 (93%) | 18 (64%) | 0.002 |
| Flows | |||
| FVC (% predicted) | 76 (61–90) | 77 (66–102) | 0.41 |
| FEV0.5 (% predicted) | 42±13 | 55±16 | <0.0001 |
| FEV0.5/FVC (% predicted) | 57±18 | 70±20 | <0.005 |
| FEF50 (% predicted) | 13.2 (7.4–26.2) | 28.4 (15.7–66.0) | <0.001 |
| FEF25–75 (% predicted) | 11.5 (7.2–21.7) | 24.7 (13.0–56.0) | <0.001 |
| Volumes | |||
| FRC (% predicted) | 112 (68–150) | 97 (69–115) | 0.14 |
| RV (% predicted) | 124 (72–171) | 108 (76–125) | 0.17 |
| TLC (% predicted) | 96 (82–120) | 85 (73–121) | 0.21 |
| RV/TLC | 54.5 (47.7–59.7) | 47.7 (43.7–54.5) | 0.002 |
| FRC/TLC | 65.1±7.4 | 57.0±9.5 | <0.0001 |
| VC (mL) | 97 (74–138) | 118 (93–154) | 0.035 |
| Compliance | |||
| CRS (% predicted) | 64 (47–99) | 74 (64–95) | 0.20 |
| CRS/kg | 1.00 (0.87–1.21) | 1.08 (0.92–1.49) | 0.30 |
Data shown as median (interquartile range), mean±sd or n (%), unless otherwise indicated. Bold text signifies p<0.05. iPFT: infant pulmonary function test; FVC: forced vital capacity; FEV0.5: forced expiratory volume in 0.5 s; FEF50: forced expiratory flow at 50% of FVC; FEF25–75, forced expiratory flow between 25% and 75% of FVC; FRC: functional residual capacity; RV: residual volume; TLC: total lung capacity; VC: vital capacity (TLC–RV); CRS: compliance of the respiratory system.