Table 3.
Competing-risk regression analysis for liberation from mechanical ventilation with death as the competing event
| Variable (reference level) | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| SHR | 95% CI | P | SHR | 95% CI | P | |
| Age | 0.964 | 0.943–0.986 | 0.002 | 0.971 | 0.946–0.996 | 0.025 |
| Sex (male) | 0.679 | 0.305–1.511 | 0.342 | – | ||
| BMI | 1.011 | 0.959–1.065 | 0.689 | – | ||
| SOFA score at admission | 0.865 | 0.770–0.970 | 0.013 | – | ||
| SAPS II score | 0.970 | 0.937–1.004 | 0.076 | – | ||
| Hypertension (yes) | 0.700 | 0.507–0.967 | 0.031 | – | ||
| Chronic ischemic heart disease (yes) | 0.468 | 0.146–1.494 | 0.200 | – | ||
| COPD (oxygen therapy/CPAP) (yes) | 0.845 | 0.208–3.431 | 0.814 | – | ||
| Chronic kidney disease (yes) | 1.216 | 0.281–5.266 | 0.793 | – | ||
| Diabetes (yes) | 0.768 | 0.451–1.310 | 0.333 | – | ||
| Chronic liver disease (MELD > 10) | 1.054 | 0.295–3.765 | 0.936 | – | ||
| Need for renal replacement therapy (yes) | 0.208 | 0.093–0.466 | 0.001 | 0.244 | 0.113–0.526 | < 0.001 |
| Late onset VAP (yes) | 0.290 | 0.174–0.483 | < 0.001 | 0.280 | 0.174–0.450 | < 0.001 |
| CRS < 40 ml/cmH2O in the first 5 days | 1.021 | 0.990–1.053 | 0.195 | – | ||
| Steroid use (yes) | 1.860 | 0.852–4.060 | 0.119 | – | ||
| PaO2/FiO2 variation after pronationb | 1.370 | 1.187–1.582 | < 0.001 | 1.563 | 1.329–1.838 | < 0.001 |
| Cardiovascular complications (yes) | 0.180 | 0.0752–0.433 | < 0.001 | 0.194 | 0.088–0.427 | < 0.001 |
| Neurologic complications (yes) | 0.376 | 0.165–0.856 | 0.020 | 0.296 | 0.110–0.798 | 0.016 |
| Digestive complications (yes) | 0.267 | 0.046–1.583 | 0.146 | – | ||
| Extra-pulmonary infections (yes) | 0.698 | 0.486–1.000 | 0.050 | – | ||
| DP before prone positioning | 0.971 | 0.890–1.058 | 0.500 | – | ||
| ARDS PaO2/FiO2 class (severe)a | 1.775 | 1.143–2.755 | 0.011 | 1.738 | 1.116–2.705 | 0.014 |
| Infection during ICU stay (yes) | 0.698 | 0.486–1.000 | 0.050 | – | ||
Significant P values are highlighted in bold
SHR subdistribution hazard ratio (SHR 1 no association between the covariate and the corresponding cumulative incidence function, SHR > 1 an increase of the covariate value is associated with an increased risk of liberation from mechanical ventilation, SHR < 1 implies the opposite), DP driving pressure, VAP ventilator associated pneumonia, CRS compliance of the respiratory system, BMI Body mass index, COPD chronic obstructive pulmonary disease, CPAP continuous positive airway pressure, ICU intensive care unit
aPer class points increase, class 1 = severe ARDS, class 2 = moderate ARDS. Reference level in branches for each covariate
bPer quartile variation, 1st quartile (< 19%), 2nd quartile (19–49%), 3rd quartile (49–100%), 4th quartile (> 100%)