Survival analysis
| Unadjusted OR (95% CI) | P value | Adjusted OR (95% CI) | P value | E value (LL CI) | |
| Logistic regression | |||||
| In-hospital mortality | 0.22 (0.10 to 0.46) | <0.001 | 0.21 (0.079 to 0.51) | 0.001 | 3.79 (2.15) |
| 30-day mortality | 0.36 (0.18 to 0.68 | 0.002 | 0.31 (0.14 to 0.67) | 0.004 | 2.99 (1.74) |
| 1-year mortality | 0.44 (0.24 to 0.79) | 0.007 | 0.38 (0.18 to 0.76) | 0.007 | 2.63 (1.56) |
| Cox regression model | |||||
| 1-year mortality | 0.50 (0.32 to 0.77) | 0.002 | 0.45 (0.27 to 0.74) | 0.002 | 2.86 (1.77) |
The adjusted models are adjusted for age, sex, FEV1 and pH at NIV initiation.
FEV1, forced expiratory volume in the first second; LL CI, lower limit of CI closest to the null; NIV, non-invasive ventilation.