Denominator in case fatality rate
Case fatality rate Total number of deaths due to a paicular disease ________________________________________ X 100 Total number of cases due to to the same disease 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 ( eg: food poisoning, cholera, measles) Case fatality is closely related to virulence. The case fatality rate for the same disease may vary in different epidemics because of changes in the agent, host and environmental factors Reference: Park&;s textbook of Preventive and Social medicine, 23rd edition, Paeg no. 58
Mid year population
Population at risk
Number of cases
Number of deaths
Communicable diseases