Table 4– Predictors of mortality in the total chronic obstructive pulmonary disease population, according to the multivariate Cox regression analysis.
| HR (95% CI) | p-value | |
| Age years | 1.030 (1.004–1.056) | 0.021 |
| PaO2 kPa | 0.851 (0.748–0.969) | 0.015 |
| TLCO % pred | 0.971 (0.957–0.984) | <0.001 |
| FEV1 % pred | 1.016 (0.974–1.060) | 0.463 |
| FVC % pred | 0.977 (0.950–1.004) | 0.090 |
| FEV1/FVC | 0.988 (0.944–1.033) | 0.582 |
| RV % pred | 0.987 (0.975–1.001) | 0.055 |
| FRC % pred | 1.021 (0.998–1.045) | 0.078 |
| TLC % pred | 1.011 (0.979–1.044) | 0.507 |
| IC/TLC % | 2.009 (0.378–3.451) | 0.628 |
| PaCO2 kPa | 0.991 (0.798–1.230) | 0.932 |
| BMI kg·m−2 | 1.006 (0.973–1.041) | 0.710 |
Carbon monoxide transfer factor (TLCO) % pred and forced expiratory volume in 1 s (FEV1) % pred entered the analysis as continuous variables. PaO2: arterial oxygen partial pressure; FVC: forced vital capacity; RV: residual volume; FRC: functional residual capacity; TLC: total lung capacity; IC: inspiratory capacity; PaCO2: arterial carbon dioxide partial pressure; BMI: body mass index.