This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
Indicator of efficacy of hospital services and health programs 
Select and explain. 
A. Case fatality rate, B. Prevalence, C. Incidence, D. Secondary attack rate
B: Prevalence
Answer: B: Prevalence 
Explanation: Case fatality rate - propoion of deaths within a designated population of cases Incidence- It is rate of new cases of diseases occuring with in a period of time Prevalance - It is actual number of cases alive with disease during a period of time. Hence it shows the efficicacy of hospital services and health programs Secondary Attack Rate - It is defined as probability of infection occuring in the susceptible individuals with in a reasonable incubation period following known contact with infected person/source