Correlation Co-efficients for pulmonary function vs disease activity
| Pulmonary function measure | 6 minute walk distance | Change in oxygen saturation | St George's questionnaire activity score | |
| Spirometry | FEV1 | 0.50 | 0.62 | -0.39 |
| FEV1 % predicted | 0.25 | 0.7 | -0.39 | |
| Impulse Oscillometry | R5 | -0.46 | 0.54 | 0.51 |
| R20 | -0.29 | 0.58 | 0.42 | |
| R5-R20 | -0.49 | 0.52 | 0.45 | |
| Interrupter technique | Rint | -0.47 | 0.63 | 0.41 |
total (R5) central (R20) small (R5-20) airways resistance