Table 6.
Principal component loadings
| Variables | Components
|
||
|---|---|---|---|
| 1 | 2 | 3 | |
| Age (years) | −0.176 | 0.706 | −0.395 |
| Smoking (pack-years) | −0.113 | 0.266 | 0.530 |
| BMI (kg/m2) | 0.502 | −0.533 | −0.175 |
| FEV1 (% pred) | 0.657 | 0.481 | −0.349 |
| RV/TLC (%) | −0.679 | −0.044 | 0.481 |
| Dlco/VA (mL/min/mmHg/L) | 0.647 | −0.433 | −0.024 |
| 6MWD (m) | 0.788 | −0.120 | 0.275 |
| BDI score | 0.721 | 0.351 | 0.306 |
| Depression score on HADS | −0.529 | −0.373 | −0.398 |
Note: Scores with factor loadings >0.50 are shown in bold.
Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in 1 second; RV, residual volume; TLC, total lung capacity; Dlco, diffusion capacity for carbon monoxide; 6MWD, 6-minute walk distance; BDI, Baseline Dyspnea Index; HADS, Hospital Anxiety and Depression Scale; DLCO/VA, DLCO divided by the alveolar volume.