Table 3. Classification of symptom severity of SARS-CoV-2 infection using the reported criteria.

SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; PaO2: partial pressure of oxygen; FiO2: fraction of inspired oxygen

Symptom severity	Description
Mild	Mild symptoms including fever, fatigue + absence of radiographic feature + absence of pneumonia-like symptom [31]
Moderate	Fever + respiratory symptoms + presence of radiographic features [31]
Severe	Dyspnea, respiration rate of >30/min or O2 saturation of <93% or PaO2/FiO2 of <300 mmHg [31]
Critical	Respiratory failure or septic shock or multiple organ failure [31]