In a population of 5000, incidence of disease is 100 in 1 year. Duration of disease studied for is 2 years. Calculate prevalence: (A) 20\/1000, (B) 40\/1000, (C) 80\/1000, (D) 400\/1000
Answer is B. Ref: Parks 23rd edition pg 61. Prevalence = Incidence x Duration = (100/5000) x 2 = (20/1000) x 2 = 40/1000