Variables | Unadjusted HR (95% CI) | p-value |
Influenza virus alone | 0.52 (0.31–0.89) | 0.02 |
Influenza virus and co-pathogen | 0.76 (0.83–1.56) | 0.46 |
Non-influenza virus pneumonia | 1.10 (0.83–1.46) | 0.49 |
Aspiration | 0.64 (0.41–0.99) | 0.048 |
Nonpulmonary sepsis | 2.40 (1.73–3.32) | <0.001 |
Miscellaneous | 0.86 (0.55–1.34) | 0.51 |
Age, per 1-year increment | 1.023 (1.013–1.033) | <0.0001 |
Male sex | 1.11 (0.83–1.60) | 0.24 |
Time of presentation to hospital to the ICU, per 1-day increment | 1.24 (0.64–1.86) | 0.59 |
Prognostic scores | ||
SAPS II at admission, per 1-point increment | 1.031 (1.024–1.038) | <0.0001 |
SOFA score on day 1 of ARDS, per 1-point increment | 1.213 (1.171–1.256) | <0.0001 |
Coexisting condition | ||
Diabetes mellitus | 1.10 (0.72–1.68) | 0.67 |
Valvular and/or coronary disease with treatment | 1.20 (0.84–1.72) | 0.31 |
Aplasia and/or recent chemotherapy for solid tumour or haematological disease | 1.45 (1.06–2.01) | 0.02 |
Cirrhosis | 2.05 (1.42–2.95) | <0.0001 |
COPD | 0.76 (0.53–1.07) | 0.14 |
Obesity | 1.05 (0.77–1.44) | 0.75 |
MV | ||
PaO2/FIO2 ratio#, per 1-mmHg increment | 0.990 (0.986–0.995) | <0.0001 |
Driving pressure#, per 1-point increment | 1.062 (1.035–1.089) | <0.0001 |
Organ support and treatments | ||
Treatment with vasopressors | 2.88 (1.47–3.62) | 0.02 |
Treatment with glucocorticoids | 1.58 (1.14–2.06) | 0.005 |
Renal replacement therapy | 2.39 (1.84–3.18) | <0.001 |
Prone positioning | 0.86 (0.64–1.13) | 0.27 |
Extracorporeal membrane oxygenation | 0.78 (0.45–1.29) | 0.34 |
ICU: intensive care unit; SAPS: Simplified Acute Physiology Score; SOFA: Sequential Organ Failure Assessment; MV: mechanical ventilation; PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction. #: worst data recorded between 12 and 24 h of MV from the diagnosis of ARDS, after optimisation of MV.