Table 4.
Relationship between pulmonary function parameters and the presence of asthma in multiple logistic regression with stepwise selection (subjects with obstructive diseases only)
| Variables | Odds Ratio (95 % Confidence limit) | p value |
|---|---|---|
| 1. | ||
| FEV1/FVC | 1.043 (1.012–1.074) | <0.0001 |
| MEF25, %predicted | 1.024 (1.010–1.038) | 0.0024 |
| PEF, %predicted | 1.018 (1.006–1.030) | 0.0088 |
| RAW, %predicted | 1.002 (1.000–1.004) | 0.0320 |
| 2. | ||
| FEV1, %predicted | 1.029 (1.013–1.046) | <.0001 |
| MEF25, %predicted | 1.022 (1.010–1.035) | 0.0015 |
| RAW, %predicted | 1.002 (1.000–1.004) | 0.0287 |
| FRC, %predicted | 0.981 (0.973–0.989) | <.0001 |
| 3. | ||
| DLCO, %predicted | 1.071 (1.051–1.090) | <.0001 |
| FEV1/FVC | 1.051 (1.024–1.078) | <.0001 |
| TLC, %predicted | 1.040 (1.014–1.067) | 0.0021 |
| FRC, %predicted | 0.970 (0.956–0.984) | 0.0041 |
1/ Variables of spirometry and resistance (initial model1: FVC, %pred, FEV1, %pred, FEV1/FVC, MEF75, %pred, MEF50, %pred, MEF25, %pred, MMEF, %pred, PEF, %pred. RAW, %pred. and sGAW, %pred.); 2/ added variables of lung volumes (initial model2: model1, TLC, %pred, RV, %pred, FRC, %pred.); 3/ added variables of diffusion capacity (initial model3: model2,DLCO, %pred, KCO, %pred.)