This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Best study is ? \nSelect and explain. \nA. Case-control study, B. Coho study, C. Meta-analysis, D. RCT', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Meta-analysis Here are the different epidemiological studies with decreasing order of accuracy to test the association between risk factor and disease : ? Systematic review and meta-analysis - Overall most reliable Randomized controlled trials (controlled clinical trails) - Most reliable individual study. Retrospective (Non-concurrent/historic) Coho study. Prospective (concurrent) Coho study. Case control study Cross-sectional study Ecological study", 'role': 'assistant'}]