Which of the following is the best parameter to predict virulence of acute infectious illness?: (A) Incidence, (B) Secondary attack rate, (C) Case fatality rate, (D) Crude death rate
Answer is C. Case fatality rate is directly related to the killing power of the disease. It denotes the virulence of an organism. But utility of case fatality rate is limited to acute illnesses and is not of much value for chronic diseases. Ref: Park 21st edition, page 55.