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Table 2 COVID-19 severity assessment (COSA) score parameters and evaluation

From: Development and validation of a prognostic COVID-19 severity assessment (COSA) score and machine learning models for patient triage at a tertiary hospital

Parameter Value Score points
Sex Male 1
CRP  ≥ 25 mg/L 3
Sodium  ≥ 144 mmol/L 2
Hemoglobin  ≤ 100 g/L 1
eGFR according to CKD-EPI  ≤ 75 mL/min 1
Glucose  ≥ 8.6 mmol/L 1
Leucocytes  ≥ 10 G/L 1
Score evaluation
Total score per patient Category % patients (training, validation) % severe outcome (training, validation)
0–3 points: Low risk for severe COVID-19 (< 5%) 37.9, 38.4% 0, 4.5%
4–5 points: Moderate risk for severe COVID-19 (< 50%) 34.8, 32.5% 24.6, 15.4%
6–7 points: High risk for severe COVID-19 (> 50%) 12.1, 19.4% 70.8, 46.1%
8–10 points: Very high risk for severe COVID-19 (> 90%) 15.2, 9.6% 96.7, 75.0%
  1. Laboratory parameters are maximal (C-reactive protein (CRP), sodium, glucose, leucocytes) or minimal (estimated glomerular filtration rate (eGFR) according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)) values 3 days prior to and up to 1 day after first positive SARS-CoV-2 testing. % patients: fraction of patients per category, % severe: fraction of patients with severe outcomes per category