Table 1. Correlation analysis among fractional-order parameters and spirometric results. Significance was analyzed after Bonferroni correction. The highest associations are described in bold.
| FEV1 (L) |
FEV1 (%) |
FVC (L) |
FVC (%) |
FEV1/FVC | FEF max (L) |
FEF max (%) |
|
|---|---|---|---|---|---|---|---|
| FrL | -0.51 <0.0001 |
-0.49 <0.0001 |
-0.49 <0.0001 |
-0.54 <0.0001 |
-0.08 ns |
-0.58 <0.0001 |
-0.62 <0.0001 |
| α | -0.22 ns |
0.001 ns |
-0.27 ns |
-0.04 ns |
0.09 ns |
-0.26 Ns |
0.002 ns |
| FrC | 0.44 <0.0005 |
0.11 ns |
0.45 0.0001 |
0.13 ns |
0.01 ns |
0.09 Ns |
-0.20 ns |
| β | 0.42 <0.0005 |
0.53 <0.0001 |
0.38 0.001 |
0.56 <0.0001 |
0.15 ns |
0.31 Ns |
0.49 <0.0001 |
| G |
-0.60 <0.0001 |
-0.49 <0.0001 |
-0.57 <0.0001 |
-0.52 <0.0001 |
-0.19 ns |
-0.30 Ns |
-0.23 ns |
| H | -0.27 ns |
0.02 ns |
-0.28 ns |
0.02 ns |
-0.01 ns |
-0.02 Ns |
0.30 ns |
| η | -0.45 0.0001 |
-0.54 <0.0001 |
-0.40 <0.001 |
-0.57 <0.0001 |
-0.17 ns |
-0.31 Ns |
-0.47 <0.0001 |
FEV1: forced expiratory volume in the first second; FVC: forced vital capacity; FEF: forced expiratory flow between 25% and 75% of the FVC; %: percentage of the predicted values. FrL: fractional-order inertance; α: fractional inertance coefficient; FrC: fractional-order compliance; β: fractional compliance coefficient; G: damping factor; H: elastance; η: hysteresivity coefficient.