Table 7.
Correlation between the IOS and spirometry parameters in geriatric COPD patients
| Z5 (%predicted) | Fres (L/s) | X5 (kPa/L/s) | R5 (%predicted) | R20 (%predicted) | R5–R20 (%predicted) | ||
|---|---|---|---|---|---|---|---|
| FVC (%predicted) | r | −0.373** | −0.253* | 0.345** | −0.337** | −0.197 | −0.390** |
| FEV1(%predicted) | r | −0.527** | −0.479** | 0.514** | −0.499** | −0.293** | −0.551** |
| FEV1/FVC (%) | r | −0.469** | −0.450** | 0.452** | −0.455** | −0.239* | −0.514** |
| MMEF (%predicted) | r | −0.456** | −0.494** | 0.445** | −0.464** | −0.345** | −0.447** |
Notes:
*
P<0.05.
**
P<0.001.
Abbreviations: IOS, impulse oscillometry; Z5, respiratory impedance; Fres, resonant frequency; X5, respiratory reactance; R5–R20, respiratory resistance; FVC, forced vital capacity; r, Pearson’s correlation coefficient; FEV1, forced expiratory volume in 1 second; MMEF, maximum midexpiratory flow rate.