Fig. 4.

This funnel plot evaluates potential publication bias in studies comparing the risk of fatigue between females and males. Each red dot represents a study included in the meta-analysis. The horizontal axis shows the RR from each study, while the vertical axis represents the standard error (SE) of the RR. Symmetry around the vertical line indicates no publication bias. The dashed lines form a funnel shape outlining the expected range of study results. Asymmetry or clustering outside the funnel may suggest potential publication bias.