Table 1.

Trial outcomes. Definitions for all outcome are provided in the statistical analysis plan available in the Supplementary Materials.

Outcomes	Variable Type	Approach to Analysis
Efficacy outcomes
COVID-19 7-point Ordinal Clinical Progression Outcomes Scale 14 days after randomization (assessed on Study Day 15)	Ordinal	Cumulative probability model with logit link
All-location, all-cause 14-day mortality (assessed on Study Day 15)	Binary	Logistic regression
All-location, all-cause 28-day mortality (assessed on Study Day 29)	Binary	Logistic regression
Survival through 28 days	Time-to-event	Proportional hazards regression
Time to hospital discharge through 28 days	Time-to-event	Multistate model with death as a competing risk
Time to recovery	Time-to-event	Cumulative probability model with logit link
COVID-19 7-point Ordinal Clinical Progression Outcomes Scale on Study Day 3, 8 and 29	Ordinal	Cumulative probability model with logit link
Oxygen-free days through Day 28	Ordinal	Cumulative probability model with logit link
Ventilator-free days through Day 28	Ordinal	Cumulative probability model with logit link
Vasopressor-free days through Day 28	Ordinal	Cumulative probability model with logit link
ICU-free days through Day 28	Ordinal	Cumulative probability model with logit link
Hospital-free days through Day 28	Ordinal	Cumulative probability model with logit link
Safety Outcomes
Receipt of renal replacement therapy	Binary	Risk difference
Venous thromboembolic disease (deep vein thrombosis or pulmonary embolism)	Binary	Risk difference
Cardiovascular event (myocardial infarction or ischemic stroke)	Binary	Risk difference
Transfusion reaction	Binary	Risk difference
Transfusion related acute lung injury (TRALI)	Binary	Risk difference
Transfusion associated circulatory overload (TACO)	Binary	Risk difference
Transfusion-related infection	Binary	Risk difference