Incidence of diarrhoea in a community can be calculated by-
Coho study is also known as incidence study. The cohos are identified prior to the appearance of disease under investigation. The study group so defined are observed over a period of time to determine the frequency of disease among them. (refer pgno:75 park 23rd edition)
Case control study
Coho study
Cross sectional study
Double blind placebo control study
Epidemiology