# Definition

The case fatality rate is the number of deaths related to a given disease out of the total number of cases of the same disease. It is expressed as a percentage.

It allows to express the seriousness of a disease and the effectiveness of a treatment. To calculate this rate, it is important to know the number of deaths due to the disease, but also the total number of people who contracted the disease.

# Not to be confused

The case fatality rate should not be confused with the death rate ( http://success.openhealth.fr/fr/articles/3947946-taux-de-mortalite ) which expresses the total number of deaths, whatever the cause , in a population and a period defined on the average total population over the same period.

# Example

1,000 people have a disease, 15 people die from the disease. Then the case fatality rate will be: