Fig. 3

Funnel plots for assessing publication bias. The funnel plots are used to visually assess publication bias across multiple studies. Each plot displays the log diagnostic odds ratio on the x-axis and the inverse standard error (SE) on the y-axis. The funnel plot is typically symmetrical in the absence of bias, with higher precision studies (smaller SE) clustering near the top and lower precision studies (larger SE) scattering toward the bottom. The open circles represent individual studies. The solid line indicates the regression line. Asymmetry in the distribution of studies relative to the regression line may suggest publication bias. Individual Plots: Plot a, b, c, d, e, and f all visually show studies distributed across the funnel. The p-value of Deeks' Funnel Plot Asymmetry Test, indicated on each plot, provides statistical evidence for asymmetry. If p > 0.05, there is no significant asymmetry, suggesting a low likelihood of publication bias. If p < 0.05, significant asymmetry is present, indicating a potential risk of publication bias