An ecological study finds a strong positive correlation (r = 0.88) between per-capita sugar consumption and type 2 diabetes prevalence across 20 countries. A researcher concludes that sugar consumption causes diabetes in individuals. This fallacy is known as:
- A Berkson's bias
- B Ecological fallacy ✓
- C Confounding by indication
- D Length-biased sampling
Correct answer: B. Ecological fallacy
Explanation
The ecological fallacy (also called the atomistic fallacy in reverse) occurs when associations observed at the group (population) level are incorrectly applied to individuals. Ecological studies use aggregate data and cannot establish individual-level causality. A country with high average sugar intake may contain many low-consuming individuals who nevertheless develop diabetes due to other factors.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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