This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
Coho study is better than case control study in all ways except 
Select and explain. 
A. Greater Comparability, B. Lesser time spent, C. Prospective analysis, D. Less Bias
B: Lesser time spent
Answer: B: Lesser time spent 
Explanation: Coho study: Involves larger no of subjects Long follow up period needed involving delayed results Expensive Yields incidence rate relative risk as well attributable risk (refer pgno:79 park 23rd edition)