More details about outcomes and disease severity


We predefined the following critical and important outcome measures:

Critical outcomes

The following outcomes with related time points reported as days (D) of follow-up were considered:

  1. Clinical improvement (D28 / ≥ D60) defined as a hospital discharge or improvement on the scale used by trialists to evaluate clinical progression and recovery. We recorded the scale and the threshold used by authors to define improvement as appropriate.
  2. WHO Clinical Progression Score of level 7 or above (i.e. mechanical ventilation +/- additional organ support [ECMO, vasopressors or dialysis] OR death (D28 / ≥ D60)
  3. All-cause mortality (D28 / ≥ D60)
  4. All assessments performed at D60 and later are reported under ≥ D60. When outcomes are assessed at time points other than those selected by the review, we chose the closest (e.g. D15 for D28).

    Safety outcomes:

    1. Incidence of any adverse events (AEs)
    2. Incidence of serious AEs (SAEs)

    Important outcomes

    1. Time to clinical improvement
    2. Time to WHO Clinical Progression Score of level 7 or above
    3. Time to death


    Disease severity was classified as described below according to the clinical status or clinical management of patients. This classification relies on existing classification and clinical expertise (WHO 2020a, WHO 2020b). We considered the description of eligibility criteria as well as the baseline characteristics of participants and classified the severity as follow: