How to Calculate Case Fatality Rate (CFR)
The Case Fatality Rate (CFR) is a crucial epidemiological measure used to understand the severity of a disease. It represents the proportion of individuals diagnosed with a specific disease who ultimately die from that disease. In simpler terms, it tells us how deadly a particular illness is among those who contract it.
The formula for calculating the Case Fatality Rate is straightforward:
CFR = (Number of Deaths from a Specific Disease / Number of Confirmed Cases of that Disease) * 100
To calculate CFR, you need two key pieces of information:
- Number of Confirmed Cases: This is the total count of individuals who have been diagnosed with the specific disease within a defined period and geographical area.
- Number of Deaths: This is the total count of individuals who have died specifically due to that same disease within the same defined period and geographical area.
It's important to note that CFR is distinct from the Infection Fatality Rate (IFR). IFR considers the number of deaths among all infected individuals, including those who were never diagnosed or confirmed. CFR, on the other hand, focuses only on confirmed cases, which can make it sensitive to testing and diagnostic capabilities. A higher CFR generally indicates a more severe or lethal disease, assuming comparable diagnostic and reporting standards across different diseases or outbreaks.