TABLE 3.
Prevalence of resting and exercise airway abnormalities in the study groups
| Control subjects | WTC Dust | Clinical referral | |
| Subjects n | 13 | 20 | 15 |
| Baseline abnormalities | |||
| Expiratory flow limitation | 3/13 (23) | 9/20 (45) | 7/15 (47) |
| Non-uniform gas distribution# | 5/12 (42) | 9/18 (50) | 9/15 (60) |
| Abnormal oscillometry | 2/13 (15) | 15/20 (75)* | 12/15 (80)* |
| Exercise abnormalities | |||
| Expiratory flow limitation | 2/13 (15) | 10/20 (50)* | 12/15 (80)* |
| Dynamic hyperinflation | 1/13 (8) | 4/20 (20) | 2/15 (13) |
| Any abnormality | 2/13 (15) | 11/20 (55)* | 13/15 (87)* |
| Post-exercise abnormalities | |||
| Reduced FEV1 | 1/13 (8) | 3/20 (15) | 3/15 (20) |
| Increased R5 | 0/13 (0) | 8/20 (40)* | 7/15 (47)* |
| Any abnormality | 1/13 (8) | 11/20 (55)* | 10/15 (67)* |
| Any exercise or post-exercise abnormality | 3/13 (23) | 16/20 (80)* | 14/15 (93)* |
Data are presented as n/N (%) unless otherwise indicated. WTC: World Trade Center; FEV1: forced expiratory volume in 1 s; R5: resistance of oscillating frequency at 5 Hz. #: data are shown for the 45 out of 48 individuals that were able to complete the plethysmography and diffusion capacity tests. *: p<0.05 versus control.