Outcomes
Death

Seven categories of the Ordinal Scale for Clinical Improvement: 
Non-hospitalized with the resumption of normal activities.Non-hospitalized but unable to resume normal activities.Hospitalized, without the need for supplemental oxygen.Hospitalized, requiring supplemental oxygen.Hospitalized, requiring high-flow nasal oxygen therapy, non-invasive mechanical ventilation, or both.Hospitalized, requiring extracorporeal membrane oxygenation, invasive mechanical ventilation, or both.Death.