The I² statistic in a meta-analysis is 75%. What does this BEST indicate?
- A 75% of studies showed a statistically significant result
- B The variance between studies is high; a random-effects model and exploration of sources of heterogeneity are warranted ✓
- C 75% of the total variance is due to within-study sampling error
- D The meta-analysis should be abandoned due to data inconsistency
Correct answer: B. The variance between studies is high; a random-effects model and exploration of sources of heterogeneity are warranted
Explanation
I² quantifies the proportion of total variability in effect estimates due to between-study heterogeneity rather than sampling variation. Values of 25%, 50%, and 75% represent low, moderate, and high heterogeneity respectively (Higgins' thresholds). High heterogeneity (I²=75%) warrants use of a random-effects model and meta-regression to identify sources, but pooling can still be done with caution.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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