What is the Mortality Rate of COVID-19?

There are two major fatality measures, Infection Fatality Rate (IFR) and Case Fatality Rate (CFR).

Infection rate refers to all individuals who contract the disease – from asymptomatic (who do not know they have the disease but are carriers) to those with severe or fatal illness.

Case rate refers to documented cases.

During an infectious disease outbreak both numbers mathematically must be approximate since the final outcome of current cases is unknown until the cases recover or die. Asymptomatic, presymptomatic (will develop symptoms) or people with mild symptoms may not be documented as cases unless they are tested. Further, despite reporting to the WHO, countries do not all use WHO’s standardized reporting methods. Statistics are a moving target during the pandemic. Even though mathematical formulas attempt to compensate for all the uncertainties during the pandemic, the statistics following the pandemic will be include all documented cases plus actuarial statistics for undocumented cases and will be somewhat different from statistics during the pandemic.

Many articles on COVID-19 mention deaths/infections, but this rate gives little real information. First, the outcome of all the “infections” in the denominator is unknown; the ratio is apples-to-apples+ oranges. Some of the “infections” (denominator) will later be added to deaths (the numerator) while still remaining in the denominator and changing the ratio. And, asymptomatic infections – anywhere from 1% (Feb.’20) to 20% (Sep.’20) to as much of 50% (Nov.’20) of infections – are likely untested and therefore never part of “infections” (denominator) but they are spreading the disease. If you want to know likelihood of infection, cases/million population is a bit more informative, though still not including any asymptomatic or presymptomatic cases.

If you want to know how deadly it is to those who get it, use the more informative deaths/completed cases ratio, because both numerator and denominator are known numbers. They represent people who tested positive and later died or recovered. During a pandemic, this is a more reliable number because it is apples-to-apples.

Best (most complete, most up-to-date) information.

Best explanation of how numbers are collected and analyzed. Next best explanation.