Table 4. Classification of Disease Based on Signs, Symptoms and Imaging.

Yu-Huan Xu et al classification
Mild	Mild clinical symptoms, no imaging presentation of pneumonia
Common	Fever, respiratory symptoms, imaging confirming pneumonia
Severe	Respiratory distress with a respiratory rate greater than 30, oxygen saturations < 93% at rest and PaO2/FiO2 < 300
Critically severe	Respiratory failure with intubation, shock, organ failure requiring care in intensive care unit
Tian et al classification
Non-pneumonia	Confirmed case with fever and/or respiratory symptoms, but no radiographic evidence of pneumonia
Mild	Confirmed case with fever, respiratory symptoms and radiographic evidence of pneumonia
Severe	Mild case with dyspnea and respiratory failure