In a case-control study of pesticide exposure and Parkinson's disease, cases are recruited from a neurological ward and controls from an orthopaedic ward. Cases with pesticide exposure are more likely to recall and report exposure than controls. This BEST exemplifies:
- A Recall bias ✓
- B Berkson's bias
- C Observer bias
- D Length-biased sampling
Correct answer: A. Recall bias
Explanation
Recall bias occurs when cases (with the disease) are more likely to remember and report prior exposures than controls, leading to differential misclassification of exposure. Berkson's bias (hospital admission rate bias) occurs when using hospitalised controls who differ systematically from the source population. Observer bias involves the assessor's knowledge affecting recording, not the subject's recall.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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