Interpreting findings from Mendelian randomization using the MR-Egger method

Mendelian randomization-Egger (MR-Egger) is an analysis method for Mendelian randomization using summarized genetic data. MR-Egger consists of three parts: (1) a test for directional pleiotropy, (2) a test for a causal effect, and (3) an estimate of the causal effect. While conventional analysis methods for Mendelian randomization assume that all genetic variants satisfy the instrumental variable assumptions, the MR-Egger method is able to assess whether genetic variants have pleiotropic effects on the outcome that differ on average from zero (directional pleiotropy), as well as to provide a consistent estimate of the causal effect, under a weaker assumption-the InSIDE (INstrument Strength Independent of…

• WT
  Wellcome Trust

  Awards: 204623/Z/16/Z, 204623
• BH
  British Heart Foundation

  Award: CH/12/2/29428
• RS
  Royal Society

  Award: 204623/Z/16/Z
• MR
  Medical Research Council

  Award: MR/L003120/1