Table 2.
Cox proportional-hazards regression models (subset A*)
| Covariate | Unadjusted model | Adjusted model with DPaw | Adjusted model with DPL | Adjusted model with plateau PL | ||||
|---|---|---|---|---|---|---|---|---|
| HR (95% CI) |
p value | HR (95% CI) |
p value | HR (95% CI) |
p value | HR (95% CI) |
p value | |
| Age |
1.026 (1.013–1.039) |
< 0.0001 |
1.025 (1.013–1.038) |
< 0.0001 |
1.026 (1.013–1.039) |
< 0.0001 |
1.026 (1.013–1.039) |
< 0.0001 |
| SOFA |
1.157 (1.103–1.214) |
< 0.0001 |
1.147 (1.091–1.206) |
< 0.0001 |
1.154 (1.098–1.213) |
< 0.0001 |
1.153 (1.097–1.212) |
< 0.0001 |
| DPaw |
1.116 (1.062–1.172) |
< 0.0001 |
1.093 (1.040–1.148) |
0.0004 | ||||
| DPL |
1.089 (1.036–1.144) |
0.0007 |
1.080 (1.028–1.134) |
0.0023 | ||||
| Plateau PL |
1.045 (1.009–1.082) |
0.0140 |
1.034 (0.999–1.070) |
0.0533 | ||||
| End-expiratory PL |
0.982 (0.942–1.023) |
0.3900 | ||||||
| AIC† of adjusted model | 1119 | 1123 | 1128 | |||||
*Subset A included 302 patients with measured esophageal pressure. Number of deaths was 107
†The model with lowest AIC is the one that explains the greatest amount of variation using the fewest possible independent variables. It addresses goodness of fit and simplicity of the model. Since the models presented in the Table have the same number of independent variables and the same sample, the model with lowest AIC is the best-fit model
AIC Akaike information criterion, SOFA Sequential Organ Failure Assessment score, DPaw airway driving pressure which is the difference between Pplat and total PEEP, DPL transpulmonary driving pressure which is the tidal change in transpulmonary pressure