Fig. 2

Forward MR analyses: Causal effect of CKD on severe COVID-19. (A) Scatter plot illustrating the relationship between severe COVID-19 and CKD using all four approaches employed in this investigation. (B) A forest plot with the MR estimate and 95% CI values for the SNPs (black line), as well as the MR-Egger and IVW findings, is displayed. (C) To determine if any specific IVs were mediating the causal impact, leave-one-out analyses were conducted. (D) To find any significant heterogeneity in the observed associations, a funnel plot was utilized. CI, confidence interval; IVW, inverse-variance weighted; CKD, chronic kidney disease; MR, Mendelian randomization; SNPs, single nucleotide polymorphisms