Which of the following statement is true -: (A) Case control study is not suitable for rare diseases, (B) Cohort study involves large number of subjects, (C) Case-control study is relatively expensive, (D) Cohort study yields relatively quick results
Answer is B. Ans. is 'b' i.e., Cohort study involves large number of subjects* Prevalence of blindness in India: 700 per 1 lakh population (0.7%) if cut of criteria is < 3/60 (WHO criteria); or 1100 per lakh population (1.1%) if cut of criteria is < 6/60 (NPCB criteria).