All of the following statements regarding case control and coho studies are true, except-
Case-control study is useful to investigate rare diseases or diseases about which little is known. But a disease which is rare in the general population (e.g, leukemia in adolescence) may not be rare in special exposure groups (e.g prenatal X- rays) (refer pgno:74 park 23 rd edition)
Coho studies are chosen based on history of 'Exposure'
Coho studies require longer time frame than case control studies
Coho studies are suitable to investigate 'rare' disease
Coho studies yield information about more than one disease
Epidemiology