Frequency of persistent respiratory symptoms and spirometry indices according to FEF25–75%
| Symptoms | FEF25–75%≥80%, n=75 (%) | FEF25–75% between 65% and 80%, n=35(%) | FEF25–75%<65%, n=67 (%) | p Value |
|---|---|---|---|---|
| Chronic cough | 28 (37.3) | 17 (48.6) | 42 (62.7) | 0.011 |
| Chronic expectoration | 20 (26.7) | 11 (31.4) | 31 (46.3) | 0.050 |
| Chronic dyspnoea | 38 (50.7) | 16 (45.7) | 45 (67.2) | 0.056 |
| Any chronic respiratory symptoms | 39 (52.0) | 21 (60.0) | 50 (74.6) | 0.020 |
| FEV1, %, median (25th–75th centiles) | 89 (82–100) | 73 (62–82) | 64 (52–73) | <0.001 |
| FVC, % (25th–75th percentiles) | 83 (74–92) | 72 (61–83) | 64 (53–77) | <0.001 |
| FEV1/FVC, mean (SD) | 0.89 (0.04) | 0.86 (0.05) | 0.81 (0.06) | <0.001 |
FEF25–75%, forced expiratory flow between 25 and 75%, FEF25–75%, forced expiratory flow between 25 and 75% of forced vital capacity. FEV1, forced expiratory volume in the first second; FVC, forced vital capacity.