Fig. 4

Funnel Plot (Review Manager 5.4) SE(MD) = Standard Error (Mean Difference). Graphically, there are no sources of heterogeneity. The presence of partial symmetry suggests the potential absence of publication bias. In detail, this funnel plot illustrates the distribution of the included data sets by plotting the standard error of the mean difference (SE[MD]) against the effect size. Each point corresponds to a single data set. A symmetric distribution of points around the pooled effect estimate implies that publication bias is unlikely, while any asymmetry could suggest the presence of small study effects or other biases. This visual tool helps us assess the robustness and consistency of meta-analytic results