COVID-19(90) Mortality(45) Patient(37) mechanical ventilation(33) outcome(31) coronavirus disease(28) acute respiratory distress syndrome(27) ICU(27) intensive care(26) intensive care unit(25) Critically ill(24) hospital(24) ARDS(22) patients(20) pandemic(20) with COVID-19(18) benefit(17) adjusted(16) risk(16) median(16) Trial(16) patients with COVID-19(16) Pneumonia(16) SARS-CoV-2(16) Primary outcome(16) Analysis(15) COVID-19 patient(15) Critically ill patient(14) Randomized(13) Influenza(13)