In the forest plot of a meta-analysis, small studies cluster asymmetrically to one side of the pooled effect line while large studies cluster symmetrically around it. The most likely explanation for this appearance is:
- A Publication bias ✓
- B Chance alpha error
- C Overmatching
- D Reverse causation
Correct answer: A. Publication bias
Explanation
The funnel plot plots study precision against effect size. In its absence, points scatter symmetrically around the pooled estimate. Asymmetry, with small studies showing exaggerated effects, classically indicates publication bias or related small-study effects, because negative or null small trials remain unpublished. Large studies are published regardless of result and therefore anchor the true effect.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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