In case fatality rate:
|A||Numerator and denominator are 2 separate quantities|
|B||Numerator and denominator are proportion of each other|
|C||Denominator is always constant|
|D||Numerator is always constant|
Case fatality rate (Ratio) –
[Total number of deaths due to a particular disease / Total number of cases due to the same disease] x 100
- Case fatality rate represents the killing power of a disease.
- It is simply the ratio of deaths to cases.
- The time interval is not specified.
- Case fatality rate is typically used in acute infectious diseases (e.g., food poisoning, cholera, and measles). Its usefulness for chronic diseases is limited, because the period from onset to death is long and variable. The case fatality rate for the same disease may vary in different epidemics because of changes in the agent, host and environmental factors.
- Case fatality is closely related to virulence.