Comparison of PFT among different groups (table 3):
Spirometry represents a useful investigation for both the severity and
follow up of ILD. Generally, in ILD, pulmonary function abnormalities
showed a restrictive pattern with decreased lung compliance as well as
lung volumes. CTD only group showed a forced expiratory volume in 1 s
(FEV1) (% predicted) 101 ± 7, forced vital capacity (FVC) (%
predicted) 95 ± 7, the mildILD group showed a FEV1% 77 ± 10, FVC% 72 ±
7, and the severeILD group showed a FEV1% 55 ± 5, FVC% 49 ± 8.