孟德尔随机化三大方法对比：IVW、MR-Egger与加权中位数如何选择？

We employed three Mendelian randomization methods to evaluate the robustness of causal relationships: inverse variance weighting (IVW), MR-Egger regression, and weighted median. Among these, the inverse variance weighting method was used as the primary analysis, which combines the Wald ratio estimates for each SNP using the inverse of their variances as weights to obtain an overall estimate of the causal effect. The MR-Egger regression method was used to detect potential directional pleiotropy and provide a pleiotropy-corrected estimate of the causal effect. The weighted median method, which can provide consistent causal estimates even if up to 50% of the weight comes from invalid instrumental variables, was used to assess the stability of the results.