Mortality SCORE for COVID-19: on-line calculator

covid-19, covid, coronavirus, mortality risk, mortality risk assessment

Mortality risk calculator for hospitalized patients diagnosed with COVID-19. 4C MORTALITY SCORE FOR COVID-19

This scale was developed specifically for hospitalized patients with COVID-19. This may not apply to outpatients. Stratification of the risk of death in hospitalized patients with COVID-19 is important for further decision-making on treatment tactics and predicting the course of the disease.


Sex at birth:

Number of comorbidities:

Respiratory rate, breaths/min:

Peripheral oxygen saturation on room air:

Glasgow Coma Scale:

Urea or BUN:
Urea <7 mmol/L (<42 mg/dL) OR BUN <19.6 mg/dL
Urea ≥7 to ≤14 mmol/L (≥42mg/dL to ≤84 mg/dL) OR BUN ≥19.6 to ≤39.2 mg/dL
Urea >14 mmol/L (>84 mg/dL) OR BUN >39.2 mg/dL

C-reactive protein, mg/L:
<50 mg/L (<5 mg/dL)
50-99 mg/L (5-9.9 mg/dL)
≥100 mg/L (≥10 mg/dL)

Mortality Score Risk group In-hospital mortality
0 0 0

To assess the risk of mortality in hospitalized patients diagnosed with COVID-19 is required a preliminary assessment of the state of consciousness on the Glasgow scale.

Following the Glasgow scale, the following parameters are assessed to assess the mortality rate from 4C:

Age, years<500
Sex at birthFemale0
Number of comorbidities*00
Respiratory rate, breaths/min<200
Peripheral oxygen saturation on room air≥92%0
Glasgow Coma Scale150
Urea or BUN (use measurement available)Urea <7 mmol/L (<42 mg/dL) OR  BUN <19.6 mg/dL0
 Urea ≥7 to ≤14 mmol/L (≥42mg/dL to ≤84 mg/dL) OR BUN ≥19.6 to ≤39.2 mg/dL1
 Urea >14 mmol/L (>84 mg/dL) OR BUN >39.2 mg/dL3
C-reactive protein, mg/L<50 mg/L (<5 mg/dL)0
 50-99 mg/L (5-9.9 mg/dL)1
 ≥100 mg/L (≥10 mg/dL)2

*Comorbidities include chronic cardiac disease, chronic respiratory disease (excluding asthma), chronic renal disease (estimated glomerular filtration rate ≤30), mild to severe liver disease, dementia, chronic neurological conditions, connective tissue disease, diabetes mellitus (diet, tablet, or insulin controlled), HIV or AIDS, and malignancy.


4C Mortality ScoreRisk groupIn-hospital mortality
0-3Low 1.2-1.7%
≥15Very high61.5-66.2%
  • Low risk – May be suitable for outpatient management
  • Intermediate risk – May be suitable for general inpatient treatment
  • High risk – May require aggressive treatment and higher level of monitoring


Apply to risk stratify patients who are admitted with COVID-19.

Designed specifically for hospitalized COVID-19 patients. This may not apply to patients seen in the outpatient setting.

Requires eight specific predictors of mortality, not all of which may be immediately available in all settings (e.g., CRP).  

Patient population in the study had a median age of 73 years old, 82% white, with an overall mortality of 32.2%. All patients were from England, Scotland, and Wales. Consider when applying this to your patient population.

Not externally validated and may lead to unknown applicability and generalizability.

Risk stratification of admitted COVID-19 patients to aid in determining mortality risk, decision for level of care, and prognostication.

The 4C Mortality Score was derived from a prospective observational cohort study based upon positively tested COVID-19 patients admitted to 260 hospitals in England, Scotland and Wales. The score includes eight variables consisting of age, sex, number of comorbidities, respiratory rate, peripheral oxygen saturation, Glasgow coma scale score, urea level, and C-reactive protein. The score, ranging from 0-21, predicts in-hospital mortality from low risk to very high risk. The score, when compared against existing scores for CAP and COVID-19, performed better in predicting in-hospital mortality in the validation cohort.

Although the score performed well in the internal validation of the study, it requires external validation. The score is limited to determining in-patient hospital mortality and is not designed to be applicable to the outpatient setting. Overall generalizability of the score needs to be further investigated as it was derived and validated in a primarily homogeneous ethnic and age cohort.

Eight specific predictors of mortality are required, not all of which may be available in all settings at once (eg, C-reactive protein).

The median age of patients in the study was 73 years, 82% were Caucasian, with an overall mortality rate of 32.2% in the group. All patients were from England, Scotland and Wales.

Be careful, this scale has not been externally validated at this time. Use with care!

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