Regression coefficients, explained variance, and significance of the independent variables that entered the regression analysis
| Dependent variable | Independent variables | β | R2 Δ | R2 | p-value |
| Dyspnoea | |||||
| Average | |||||
| Dyspnoea today# | 0.64 | 0.45 | 0.45 | <0.001 | |
| P a,O2 rm | −0.41 | 0.13 | 0.58 | 0.010 | |
| MMSE | −0.34 | 0.10 | 0.68 | <0.010 | |
| Greatest | |||||
| Dyspnoea today# | 0.53 | 0.31 | 0.31 | 0.001 | |
| FVC % pred | 0.34 | 0.13 | 0.41 | 0.020 | |
| Least | |||||
| Dyspnoea today# | 0.35 | 0.25 | 0.25 | 0.005 | |
| MMSE | −0.50 | 0.23 | 0.48 | 0.002 | |
| Fatigue | |||||
| Average | |||||
| Fatigue today¶ | 0.84 | 0.70 | 0.70 | <0.001 | |
| Greatest | |||||
| Fatigue today¶ | 0.66 | 0.44 | 0.44 | <0.001 | |
| Least | |||||
| Fatigue today¶ | 0.64 | 0.36 | 0.36 | 0.001 |
β: standardized regression coefficient
R2 Δ: coefficient of determination associated with each independent variable
R2: cumulative standardized coefficient of determination
Pa,O2rm: oxygen tension in arterial blood taken while on room air
MMSE: Mini Mental State Exam
FVC: forced vital capacity
#: dyspnoea today score taken from the Pulmonary Functional Status and Dyspnoea Questionnaire-Modified version (PFSDQ-M) general dyspnoea question number four
¶: fatigue today taken from the PFSDQ-M general fatigue question number four