All of the following are analytical epidemiological studies except-: (A) Coho study, (B) Case - control study, (C) Ecological study, (D) Field trial
Answer is D. 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)