What is a common method to detect publication bias in meta-analysis?

What is a common method to detect publication bias in meta-analysis?

• A. The I^2 statistic indicates publication bias.
• B. Funnel plot asymmetry is a common detection method.
• C. P-values from the meta-analysis determine publication bias.
• D. Publication bias cannot be detected statistically.

Answer: (B)

Detecting publication bias in meta-analysis is often done with a funnel plot that plots each study’s effect size against its precision. In the absence of bias, the results should form a symmetric funnel because sampling variation is the main driver of spread, with larger, more precise studies clustered near the true effect and smaller studies scattered at the bottom. If there’s publication bias, especially against non-significant findings, the plot tends to become asymmetric, indicating that some small studies may be missing from the literature. This visual approach is widely used and can be supplemented by formal tests for asymmetry, such as Egger’s test. The I^2 statistic measures how much results differ across studies (heterogeneity) and does not diagnose publication bias, and P-values from the meta-analysis tell you about the significance of the pooled effect, not about bias in study selection.

Detecting publication bias in meta-analysis is often done with a funnel plot that plots each study’s effect size against its precision. In the absence of bias, the results should form a symmetric funnel because sampling variation is the main driver of spread, with larger, more precise studies clustered near the true effect and smaller studies scattered at the bottom. If there’s publication bias, especially against non-significant findings, the plot tends to become asymmetric, indicating that some small studies may be missing from the literature. This visual approach is widely used and can be supplemented by formal tests for asymmetry, such as Egger’s test. The I^2 statistic measures how much results differ across studies (heterogeneity) and does not diagnose publication bias, and P-values from the meta-analysis tell you about the significance of the pooled effect, not about bias in study selection.