A cross-sectional survey finds higher rates of diabetes among individuals who exercise regularly compared to those who do not. The most plausible explanation for this counterintuitive finding is:
- A Confounding by age
- B Neyman's survival bias
- C Reverse causation ✓
- D Detection bias
Correct answer: C. Reverse causation
Explanation
Reverse causation is a major limitation of cross-sectional studies: the temporal sequence of exposure and outcome cannot be established. Here, individuals diagnosed with diabetes may have initiated regular exercise as part of disease management, making it appear that exercise 'causes' diabetes. Neyman's bias relates to selective survival affecting case detection. Detection bias arises when the diagnosis rate differs between groups due to screening intensity, which is less plausible here.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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