A case-control study finds OR = 3.2 for pesticide exposure and non-Hodgkin lymphoma. Cases were recruited from tertiary cancer hospitals while controls were healthy hospital visitors. This is MOST likely an example of:
- A Berkson's bias (hospital admission bias) ✓
- B Recall bias
- C Neyman bias (incidence-prevalence bias)
- D Observer bias
Correct answer: A. Berkson's bias (hospital admission bias)
Explanation
Berkson's bias (hospital admission bias) arises when both cases and controls are drawn from hospital populations; hospital patients have higher rates of many diseases and exposures compared with the general population, making controls unrepresentative. Using healthy hospital visitors as controls may produce spurious associations if they share different exposure profiles than community controls. Recall bias relates to differential memory of past exposure, while Neyman bias affects survivors in prevalence studies.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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