Yao (2020)
Retrospective study of risk factors for severe SARS-Cov-2 infections in hospitalized adult patients.
Sequential Organ Failure Assessment (SOFA) score (1 unit increase vs. SOFA score: 0)
COVID-19 (death)
Odds ratio: 2.402 (1.313-4.395) Adjusted model


Retrospective cohort study

Medical records


All adult patients (>=18 years old) consecutively admitted in Dabieshan Medical Center from January 30, 2020 to February 11, 2020 were collected and reviewed.

The degree of severity of COVID-19 was categorized as non-severe in 83(76.9%) patients, severe-alive in 13(12.0%) patients and severe-dead in 12(11.1%) patients. The median age of 108 atients with COVID-19 was 52.0 years (IQR37.0-58.0).The severe-dead patients (65.0, 51.0-73.5) were older than those severe-alive (56.0, 50.5-63.5) or non-severe patients (50.0, 34.0-56.0). The proportion of patients over 70 years old was the highest in the severe-dead group. Only patients diagnosed with COVID-19 on admission according to WHO interim guidance before admission were included


COVID-19 (death)


The degree of severity of COVID-19 (severe vs. non-severe) was defined according to the American Thoracic Society guidelines for community-acquired pneumonia. Briefly, severe COVID-19 should reach the following either one major criterion or three or more minor criteria. Minor criteria included respiratory rate more than 30 breaths per minute, PaO2/FIO2 ratio lower than 250, multilobar infiltrates confusion or disorientation, blood urea nitrogen level more than 7.1mmol/L, white blood cell count less than 4.0×109 per L, platelet count less than 100×1012 per L, core temperature lower than 36?, hypotension requiring aggressive fluid resuscitation. Major criteria included septic shock with need for vasopressors, or mechanical ventilation. Fever was defined as axillary temperature of at least 37·3°C. Sepsis and septic shock were defined according to the 2016 Third International Consensus Definition for Sepsis and Septic Shock . Acute kidney injury was diagnosed according to the KDIGO clinical practice guidelines and acute respiratory distress syndrome (ARDS) was diagnosed according to the Berlin Definition. Acute cardiac injury was diagnosed if serum levels of cardiac biomarkers (eg, high-sensitive cardiac troponin I) were above the 99th percentile upper reference limit, or if new abnormalities were shown in electrocardiography and echocardiography


Sequential Organ Failure Assessment (SOFA) score

higher SOFA (OR 2.402, 1.313-4.395; p=0.004) on admission was the independent risk factor for death

SOFA score: 0

1 unit increase

Odds ratio

2.402 (1.313-4.395)




Sequential Organ Failure Assessment (SOFA) and lymphocyte count (0.8×10^9per L)

higher Sequential Organ Failure Assessment (SOFA) score and lymphocytopenia on admission were associated with greater risk of developing severe COVID-19.