Case fatality refers to the proportion of individuals with a particular disease or condition who die from it within a specified time period. It is often used as a measure of the severity or lethality of a disease. Here's a more detailed look:

Definition: Case Fatality Rate (CFR): The proportion of individuals diagnosed with a specific disease who die from that disease. It is usually expressed as a percentage.

Case Fatality Rate (CFR) = ( Number of deaths due to the disease Number of diagnosed cases of the disease ) × 100 Case Fatality Rate (CFR)=( Number of diagnosed cases of the disease Number of deaths due to the disease ​ )×100 Examples and Use: Infectious Diseases: CFR is commonly used for infectious diseases like influenza, Ebola, and COVID-19. For instance, if 100 people are diagnosed with a disease and 10 of them die from it, the CFR is 10%.

Chronic Diseases: CFR can also be applied to chronic conditions like cancer or heart disease to understand the risk of death among those diagnosed.

Factors Affecting CFR: Disease Severity: More severe diseases tend to have higher CFRs. Health Care Access: Improved medical care can reduce CFRs. Demographic Factors: Age, sex, and comorbid conditions can influence CFR. Reporting and Data Quality: Accurate and timely data collection is crucial for reliable CFR estimates. Differences from Other Metrics: Mortality Rate: Unlike CFR, which is specific to those with the disease, the mortality rate reflects the number of deaths in the entire population over a period of time, regardless of disease status.

Survival Rate: This is the proportion of people who survive a specific disease over a defined period, which is the complement of the case fatality rate. If the CFR is 10%, the survival rate is 90%.

Applications: Public Health: CFR helps in assessing the impact of a disease on a population and in guiding public health responses and resource allocation. Clinical Research: It provides insight into the effectiveness of treatments and interventions. Understanding case fatality is important for evaluating disease impact, planning public health interventions, and guiding patient care strategies.