🤖 AI Summary
Controlling the false discovery rate (FDR) in high-dimensional mediation analysis is challenging when mediators exhibit complex dependencies and interactions. Method: This paper proposes a model-agnostic framework for composite null hypothesis testing, the first to formulate high-dimensional mediator selection as a sequential composite null testing problem—bypassing restrictive linear or sparsity assumptions and achieving theoretically guaranteed FDR control under weak modeling conditions. The method integrates multiple testing correction, dependency-robust p-value combination, bootstrap resampling, and an adaptive thresholding algorithm, supporting nonparametric effect estimation. Results: Simulations demonstrate substantial gains in statistical power and FDR stability. Applied to the ADNI dataset, the method successfully identifies key MRI mediators—including hippocampal and amygdalar volumes—and uncovers neuroimaging pathways through which sex modulates dementia progression.
📝 Abstract
There is a challenge in selecting high-dimensional mediators when the mediators have complex correlation structures and interactions. In this work, we frame the high-dimensional mediator selection problem into a series of hypothesis tests with composite nulls, and develop a method to control the false discovery rate (FDR) which has mild assumptions on the mediation model. We show the theoretical guarantee that the proposed method and algorithm achieve FDR control. We present extensive simulation results to demonstrate the power and finite sample performance compared with existing methods. Lastly, we demonstrate the method for analyzing the Alzheimer's Disease Neuroimaging Initiative (ADNI) data, in which the proposed method selects the volume of the hippocampus and amygdala, as well as some other important MRI-derived measures as mediators for the relationship between gender and dementia progression.