Table S4.
Performance properties of PEF thresholds for differentiating milder cases of COPDa from patients without COPDb by sex
| Males (n=66)
| |||||||
|---|---|---|---|---|---|---|---|
| Property | PEF threshold (L/min)c
|
||||||
| 350 | 375 | 400 | 425 | 450d | 475 | 500 | |
| Sensitivity (%) | 37.5 | 52.5 | 65.0 | 80.0 | 80.0 | 82.5 | 85.0 |
| Specificity (%) | 88.5 | 88.5 | 80.8 | 69.2 | 65.4 | 53.8 | 50.0 |
| Error (%) | 42.4 | 33.3 | 28.8 | 24.2 | 25.8 | 28.8 | 28.8 |
| Females (n=94)
| ||||||
|---|---|---|---|---|---|---|
| Property | PEFc threshold (L/min)
|
|||||
| 250 | 275 | 300 | 325 | 350d | 375 | |
| Sensitivity (%) | 39.4 | 66.7 | 69.7 | 75.8 | 87.9 | 93.9 |
| Specificity (%) | 91.8 | 86.9 | 85.2 | 80.3 | 67.2 | 42.6 |
| Error (%) | 26.6 | 20.2 | 20.2 | 21.3 | 25.5 | 39.4 |
Notes:
a
COPD, FEV1 60%–80% predicted and no history of exacerbations >12 months.
b
No known diagnosis or treatment for COPD and FEV1/FVC ≥0.70.
c
PEF rate, L/min.
d
Selected threshold.
Abbreviations: FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; PEF, peak expiratory flow.