Respiratory parameters measured at diagnosis and the follow-up visit
| Diagnosis | Follow-up | |
| FVC % pred | 98.1±1.2¶ | 94.4±1.4§ |
| FEV1 % pred | 98.8±1.6 | 98.1±1.7 |
| FEV1/FVC ratio | 77.4±0.8 | 77.1±0.7 |
| Airway obstruction# | 33.3% | 37.9% |
| FEV1/FVC <75% | ||
| PD20 mg | 0.466 (1.12)+ | 1.042 (1.11)ƒ |
FVC: forced vital capacity
FEV1: forced expiratory volume in one second
PD20: provocative dose of methacholine causing a 20% fall in FEV1
#: criteria from the American Thoracic Society
1986 15; ¶: predicted values from Commissions des Communautes Europeennes 16
+: geometric (G) mean and Gsem
§: significantly different from FVC (% pred) at diagnosis
by use of Mann-Whitney test
p<0.05
ƒ: significantly different from PD20 at diagnosis by use of Mann-Whitney test
p<0.001