This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Which one of the following is a good index of the severity of an acute disease ? 
Select and explain. 
A. Cause specific death rate, B. Case fatality rate, C. Standardized mortality ratio, D. Five year survival
B: Case fatality rate
Answer: B: Case fatality rate 
Explanation: Case fatality rate is a proportion and not a rate or ratio.

Case fatality rate (ratio)

CFR represents the killing power (severity) of a disease.

CFR = Total no. of deaths due to disease / Total no. of cases of the same disease x 100