This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Confounding and Bias, Subject name: Social & Preventive Medicine
[{'content': 'Allowing equal interview time to cases and controls can reduce which of the following bias? \nSelect and explain. \nA. Berkesonian bias, B. Recall bias, C. Selection bias, D. Interviewer bias', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Bias: - Type of systematic error. - Subject bias - Recall bias ; Hawthorn bias . - Investigatory bias: Interviewer bias, selection bias, misclassification bias. Allowing equal time for interview can take care of interviewer bias to some extent. Interviewer bias happens in case-control studies where the interviewer knows about the disease status of the person and probes more for exposure amongst cases as compared to controls. - Analyzer bias : Calculation bias - not seen now a days.', 'role': 'assistant'}]