Estimating and testing targeted mediation effect in the presence of high-dimensional mediators

Thursday, November 8, 2018 - 3:00pm - 3:30pm
Lind 305
Lei Liu (Washington University School of Medicine)
Mediation analysis has been commonly used to study the effect of an exposure on an outcome through a mediator. In practice, we may face the problem to estimate and test a specific mediator of interest, termed “targeted mediator, in the presence of high dimensional mediators. In this talk we present a de-biased Lasso estimate for the targeted mediator and derive its standard error estimator, which can be used to develop a test procedure for the targeted mediation effect. Extensive simulation studies are conducted to assess the performance of our method. We apply the proposed approach to test the mediation effects of human gut microbiome between the dietary fiber intake and body mass index.