Table 4.
Univariable and multivariable analysis for hospital mortality
| Predictor | Univariable analysis | Multivariable analysis | ||
|---|---|---|---|---|
| Odds ratio [95% CI] | p-value | Odds ratio [95% CI] | p-value | |
| Age (years) | 1.05 [1.03, 1.08] | < 0.001 | 1.05 [1.03, 1.08] | < 0.001 |
| Male | 1.02 [0.57, 1.85] | 0.95 | ||
| APACHE II | 1.04 [0.99, 1.09] | 0.12 | ||
| Non-respiratory SOFA score | 1.12 [1.03, 1.22] | 0.007 | 1.11 [1.00, 1.23] | 0.05 |
| Admission source | ||||
| Emergency | 0.85 [0.46, 1.61] | 0.62 | ||
| Elective | 1.41 [0.39, 4.84] | 0.58 | ||
| Medical | 0.96 [0.54, 1.70] | 0.89 | ||
| Surgical | 1.48 [0.82, 2.68] | 0.19 | ||
| ARDS severitya | ||||
| Moderate | 0.79 [0.42, 1.47] | 0.46 | ||
| Severe | 0.57 [0.23, 1.32] | 0.20 | ||
| ARDS risk factor | ||||
| Trauma | 0.58 [0.25, 1.25] | 0.18 | ||
| Pneumonia | 1.26 [0.68, 2.39] | 0.46 | ||
| Non-pulmonary sepsis | 1.62 [0.78, 3.37] | 0.19 | ||
| Baseline ventilation parameters | ||||
| Tidal volume (ml/kg PBW) | 1.03 [0.88, 1.20] | 0.71 | ||
| PEEP (cmH2O) | 0.87 [0.77, 0.97] | 0.01 | 0.86 [0.75, 0.98] | 0.03 |
| Mean airway pressure (cmH2O) | 0.95 [0.89, 1.00] | 0.15 | ||
| Lactate (mmol/L) | 1.17 [1.00, 1.37] | 0.05 | 1.13 [0.93, 1.39] | 0.21 |
| Vasopressor use | 1.70 [0.95, 3.08] | 0.08 | ||
| Adjunctive therapies | ||||
| Neuromuscular blockade | 0.52 [0.27, 0.98] | 0.05 | ||
| Nitric oxide | 1.12 [0.46, 2.61] | 0.79 | ||
| Prone positioning | 0.92 [0.27, 2.76] | 0.88 | ||
| Highest PaO2 (kPa/mmHg) | ||||
| Quadratic term | 1.00 [1.00, 1.00] | 0.09 | ||
| Linear term | 0.88 [0.76, 1.01] | 0.09 | ||
| Highest FiO2 | 1.00 [0.91, 1.09] | 0.96 | ||
| Highest P/F ratio | 0.98 [0.96, 1.00] | 0.10 | ||
| Average time-weighted PaO2 (kPa/mmHg) | ||||
| Quadratic term | 1.07 [1.01, 1.14] | 0.03 | 1.09 [1.02, 1.18] | 0.02 |
| Linear term | 0.17 [0.04, 0.73 | 0.02 | 0.11 [0.01, 0.63] | 0.02 |
Average time-weighted PaO2 was obtained by calculating the value between consecutive time points prior to multiplying this value by the period of time between these points. The sum of these time-weighted values was then divided by the total time of mechanical ventilation (up to 7 days from onset of ARDS) within the timepoints of interest
APACHE II, Acute physiology and chronic health evaluation II; SOFA, Sequential organ failure assessment score; PaO2, partial pressure of arterial oxygen; FiO2, Fraction of inspired oxygen; P/F ratio, partial pressure of arterial oxygen to fraction of inspired oxygen ratio; PBW, predicted body weight; PEEP, Positive end-expiratory pressure
aThe reference category for the comparison was Mild