Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator.

ABSTRACT: Developments in genome-wide association studies and the increasing availability of summary genetic association data have made application of Mendelian randomization relatively straightforward. However, obtaining reliable results from a Mendelian randomization investigation remains problematic, as the conventional inverse-variance weighted method only gives consistent estimates if all of the genetic variants in the analysis are valid instrumental variables. We present a novel weighted median estimator for combining data on multiple genetic variants into a single causal estimate. This estimator is consistent even when up to 50% of the information comes from invalid instrumental variables. In a simulation analysis, it is shown to have better finite-sample Type 1 error rates than the inverse-v

SUBMITTER: Bowden J 

PROVIDER: S-EPMC4849733 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature