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
For hospital cases and controls, there is different rates of admission to hospitals for people with different diseases, it will lead to what bias? 
Select and explain. 
A. Hawthorne effect, B. Berkesonian bias, C. Ecological fallacy, D. Interviewer bias
B: Berkesonian bias
Answer: B: Berkesonian bias 
Explanation: Bias Feature Berkesonian bias Different rates of admission to hospitals for people with different diseases Interviewer bias When the interviewer knows the hypothesis and also knows who the cases are Ecological fallacy Assigning people into groups irrespective of the characteristics they may or may not possess Hawthorne effect When subjects of an experimental study change or improve the behavior being evaluated only