Spirometry results for the asymptomatic and symptomatic cohorts
| Asymptomatic cohort# | Symptomatic cohort | p-value | |
| Spirometry parameters median (interquartile range) | |||
| FEV1 % predicted | 98.2 (16.7) | 91.4 (19.7) | <0.0001 |
| FVC % predicted | 99.4 (15.6) | 92.3 (20.4) | <0.0001 |
| FEV1/FVC % | 79.3 (8.2) | 80.0 (8.0) | ns |
| Spirometry pattern n (%) | |||
| Normal | 409 (87.6) | 621 (73.2) | <0.0001 |
| Obstructed | 30 (6.4) | 60 (7.1) | ns |
| Low FVC | 26 (5.6) | 147 (17.3) | <0.0001 |
| Obstructed and low FVC | 2 (0.4) | 20 (2.4) | <0.01 |
FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ns: not significant. #: valid spirometry data were not available in eight subjects from the asymptomatic cohort.