Incidence rate can be calculated from:
Only Coho study follows patient for a definite time period. It proceeds from cause to effect. So incidence can be calculated. Besides relative risk as well as attributable risk are also derived from coho study. While case control study study yields only estimate of relative risk. Cross sectional study yields prevalence rate. Ref: Park 21st edition, page 71.
Coho study
Case control study
Cross sectional study
Descriptive study