Exposure to multiple outcomes can be studied in
In Coho study, multiple outcomes can be studied together. In Case control study, multiple exposures can be studied together. COHO STUDY: Time consuming & expensive study Incidence & RR can be calculated No recall bias Ethical problems are present & is not useful for rare diseases Loss of follow-up can be seen - max allowable attrition rate is < 5% ; ideal retention rate >= 95% HAWTHORN BIAS - study subjects alter their behavior without notice ; can be seen.
Coho study
Case control study
Cross sectional study
Ecological study
Classification, Coho Study