EDU | What is Case Fatality Rate (CFR)?

By Editor-In-Chief on July 10, 2020 • ( Leave a comment )

CDC: Principles of Epidemiology in Public Health Practice, Third Edition, An Introduction to Applied Epidemiology and Biostatistics

Case-fatality rate

The case-fatality rate is the proportion of persons with a particular condition (cases) who die from that condition. It is a measure of the severity of the condition. The formula is:

Number of cause-specific deaths among the incident cases

Total number of incident cases

× 10 ⁿ

The case-fatality rate is a proportion, so the numerator is restricted to deaths among people included in the denominator. The time periods for the numerator and the denominator do not need to be the same; the denominator could be cases of HIV/AIDS diagnosed during the calendar year 1990, and the numerator, deaths among those diagnosed with HIV in 1990, could be from 1990 to the present.

A mortality rate is a measure of the frequency of occurrence of death in a defined population during a specified interval. Morbidity and mortality measures are often the same mathematically; it’s just a matter of what you choose to measure, illness or death.

How is CFR Determined?

CFR is presented as a percentage (0%-100%) or a ratio (between 0-1) and measures the number of confirmed deaths among the number of confirmed diagnosed cases of a particular disease at a given time.

Case Fatality Rate (CRF) measures the severity of a particular disease by defining the total number of deaths as a proportion of reported cases of a specific disease at a specific time.

This is different from general mortality rates which are the number of general deaths that occur within a population (normalized to the population) at any given time.

By Osman Shabir, M.Sc.Reviewed by Emily Henderson, B.Sc.