Predictors of mortality: univariate analysis
| Hazard ratio(crude) | 95% CI | p value | |
|---|---|---|---|
| BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; Pao2, Paco2, arterial oxygen and carbon dioxide tensions; LTOT, long term oxygen therapy. | |||
| Group A, no acute exacerbations of COPD; group B, 1–2 acute exacerbations of COPD (emergency visits or hospital admissions); group C, ⩾3 acute exacerbations of COPD. | |||
| Age (years) | <0.001 | ||
| <65 | – | – | |
| 65–74 | 1.76 | 0.88 to 3.52 | |
| ⩾75 | 5.26 | 2.70 to 10.24 | |
| Current smoking | 0.97 | 0.63 to 1.48 | 0.873 |
| Cumulative smoking (pack years) | 1.00 | 0.99 to 1.01 | 0.973 |
| Co-morbidity index | 1.43 | 1.28 to 1.60 | <0.001 |
| Charlson index | 0.002 | ||
| 0 | 1.00 | – | |
| 1 | 1.32 | 0.84 to 2.07 | |
| ⩾2 | 2.20 | 1.41 to 3.43 | |
| BMI (kg/m2) | 0.94 | 0.89 to 0.99 | 0.034 |
| Postbronchodilator FEV1 (% predicted) | 0.96 | 0.94 to 0.98 | <0.001 |
| GOLD stage | <0.001 | ||
| I | 1.00 | – | |
| II | 3.40 | 0.81 to 14.21 | |
| III | 5.34 | 1.29 to 22.07 | |
| IV | 8.34 | 2.01 to 34.55 | |
| FVC (% predicted) | 0.98 | 0.97 to 0.99 | 0.009 |
| Pao2/Fio2 | 0.99 | 0.98 to 0.99 | <0.001 |
| Paco2 (kPa) | 1.05 | 1.04 to 1.09 | <0.001 |
| LTOT | 3.42 | 2.36 to 4.95 | <0.001 |
| Acute exacerbation groups | <0.001 | ||
| Group A | 1.00 | – | |
| Group B | 2.20 | 1.45 to 3.33 | |
| Group C | 4.30 | 2.62 to 7.02 | |