Fig. 1
From: Severe COVID-19 and chronic kidney disease: bidirectional mendelian randomization study
Description of the study design of the bidirectional MR analysis. (A) The three central assumptions of MR analysis. (B) The forward MR analyses are depicted in red, with CKD serving as the exposure factor and severe COVID-19 as the outcome. The reverse MR analyses are shown in blue, with severe COVID-19 as the exposure factor and CKD as the outcome. LD, linkage disequilibrium; CKD, chronic kidney disease; MR, Mendelian randomization; SNPs, single nucleotide polymorphisms