Fig. 4: Primary endpoint of the trial (ranked severity score).

Participants were ranked hierarchically according to their clinical course. The primary endpoint of the trial was a global rank score that ranked patient outcomes according to five factors, shown as tiers from top to bottom (labelled as subsets 1–5). The left-sided icons (walking person and person in hospital bed) indicate the participant status at the time of enrolment (outpatient and inpatient, respectively). The top tier included inpatients and outpatients, whereas other subsets included inpatients or outpatients, but not both. Outcomes of hypothetical participants are represented within each tier by the right-pointing arrows. The icons on the right of the arrows represent the participant status at trial completion or at the time of the relevant outcome event (such as death, hospital discharge or hospital admission). Participants were ranked within each tier according to the following specific criteria: tier 1, time to death (ranked from shortest to longest, up to 30 d after randomization); tier 2, for participants enrolled as inpatients, the number of days supported by mechanical ventilation (invasive or noninvasive) or ECMO (until hospital discharge, up to 30 d after randomization, ranked from longest to shortest); tier 3, for participants enrolled as inpatients who did not require mechanical ventilation or ECMO, the FiO₂/SpO₂ ratio area under the curve until hospital discharge, up to 30 d after randomization, ranked from highest to lowest; tier 4, for participants enrolled as outpatients who were subsequently hospitalized, the number of days out of the hospital during the 30-d period following randomization (ranked from lowest to highest); tier 5, for participants enrolled as outpatients who did not get hospitalized during the 30 d observation period, the modified dyspnoea Borg scale (mean value of assessments at ~5, ~10 and ~15 d, ranked from highest to lowest). AUC, area under the curve.