CT severity score in COVID-19 patients, assessment of performance in triage and outcome prediction: a comparative study of different methods

Table 2 Clinical severity of COVID-19

Measured indicator/severity^a	Mild	Moderate	Severe	Critical
Respiratory rate	≥ 24	≥ 30	–	–
SPO₂	≥ 93	93 > SPO₂ ≥ 90	89 > SPO₂ ≥ 85	< 85^b
Respiratory distress	None	None	Mild to moderate	Severe^c
Blood pressure	–	–	–	< 90/60

^aPresence of any of the severity indicators of the more severe group places the patient in the more severe group
^bDespite high-flow O₂ administration
^cNasal flaring, air hunger, intercostal retraction, subcostal retraction