<prompt> All of the following are analytical epidemiological studies except-Coho studyCase - control studyEcological studyField trial  <response>: Analytical studies include: Ecological or correlational-with populations as a unit of study Cross-sectional or prevalence-with individuals as a unit of study Case-control or case reference-with individual as a unit of study Coho or followup-with individual as a unit of study refer pg no:62 park 23rd edition 