Which of the following statement is true -
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).
Case control study is not suitable for rare diseases
Cohort study involves large number of subjects
Case-control study is relatively expensive
Cohort study yields relatively quick results
Epidemiology