What is Your COVID-19 Death Score?

A paper published today presents an easy to use risk stratification score developed and validated based on parameters available to doctors when COVID-19 patients are admitted to the hospital.

The 4C Mortality Score outperformed existing scores, showed utility to directly inform clinical decision making, and can be used to stratify patients admitted to hospital with COVID-19 into different management groups. The score should be further validated to determine its applicability in other populations.

The score comes from 8 factors, two of which are lab values (CRP, urea) but 5 of which are parameters that individuals either know (age, sex, comorbidities) or which are measurable at home on themselves with home monitoring devices (respiratory rate and peripheral oxygen saturation)

Add your score up and you can predict your chances of death from these charts.

A score of 20 gives you >80% chance of death whereas a 9 puts you at 20%.

With these charts and scores we can see how much greater the mortality is for a 66 year old, let’s say compared to one less than 50 years of age. Increasing a 9 by the +4 score increases the score to 13 and the mortality rate from 20% to around 40%.

It’s also interesting that 92% is the cut-point at which a low oxygen saturation adds points. More on this later but as I pointed out in my piece on buying a home oximeter, one study found 92% to be the oxygen saturation at which patients should head to the hospital.

Thanatoscoringly Yours,



Comorbidities collected were 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. These conditions were selected a priori by a global consortium to provide rapid, coordinated clinical investigation of patients presenting with any severe or potentially severe acute infection of public interest and enabled standardisation.

Clinician defined obesity was also included as a comorbidity owing to its probable association with adverse outcomes in patients with covid-19.


10 thoughts on “What is Your COVID-19 Death Score?”

  1. This is somewhat misleading and overstates the probability of death for an individual who does not currently have Covid-19. The study is predicting probability of death given you are admitted to the hospital with Covid-19. The values used by their model would be the values when the patient is admitted which for many of the measures will presumably be worse than for someone who is not sick (which likely explains why 92 is the cutoff for O2 saturation). You can’t just take your current values and plug them in and get a realistic probability. Using A for admitted to the hospital, D for die from Covid-19, and prime (‘) for the complement, P(D) = P(D|A)P(A) + P(D|A’)P(A’). They are calculating P(D|A). Presumably with good medical care and sufficient capacity in the health care system, P(D|A’) will be essentially zero so the true probability is going to hinge critically on P(A), and of course how sick you are when you are admitted.



    • Michael,
      The second sentence includes this line “can be used to stratify patients admitted to hospital with COVID-19 into different management groups.”
      So I think it clearly is not talking about individuals without COVID-19.
      Dr P

      • Agreed, my suggestion that it was misleading was the title of the piece. The “death score” referenced in the title does not apply to the vast majority of people reading this, only to the small fraction with Covid-19 and ill enough to be admitted to the hospital. It would be nice if we could each estimate our risk of death, were we to get Covid-19, given our personal situation but that still seems elusive.

        • Michael,
          Agreed. The title could be misconstrued but within the first two sentences a discerning reader should know that this is a totally different risk of death than the infection fatality rate (which I discussed in a post on the death rate of Hoosiers in an earlier post.)
          I lamented the absence of more precise information on age and IFR in that piece.
          But for those who end up in the hospital this current piece adds some information on the relative risk of death in different decades over age 50. It also sends a signal that O2 saturation <93% is an important risk factor.

  2. Dear tSC,
    I am curious. The Charlson Index doesn’t include HPTN as a comorbidity but others do. Regardless, do you believe treated HPTN carries the same risk as untreated? Asking for a friend.

  3. These are goal posts and ignore the fact that patients are unique individuals and leave little room fir personalized medicine. A physician’s job is try to best he/she can is with due diligence and all his/her energies and intelligence. It is a calling, not a technician’s job. Otherwise corporate medicine can institute an algorithm for ‘providers’ to follow.


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