Table 1.

WHO 8-point ordinal scale for clinical status assessment

Patient status	Score
Uninfected: No clinical or virological evidence of infection	0
Ambulatory, with no limitation of activities.	1
Ambulatory, with limitation of activities.	2
Hospitalized, not requiring supplemental oxygen	3
Hospitalized, requiring low-flow supplemental oxygen (mask or nasal prongs)	4
Hospitalized, on non-invasive ventilation or high-flow oxygen devices.	5
Hospitalized, intubated and mechanical ventilation.	6
Hospitalized, on invasive mechanical ventilation and additional organ support: extracorporeal membrane oxygenation (ECMO), renal replacement therapy, pressors.	7
Death	8