【学术讲堂】统计学: When mediation analysis faces subgroup heterogeneity

发布者:英国威廉希尔唯一官网发布时间:2023-06-12浏览次数:935

【专家简介】:黄超,现任佛罗里达州立大学统计系助理教授,于2008年,2014年在东南大学分别获得应用数学学士和博士学位,2019年在美国北卡罗来纳大学教堂山分校获得生物统计博士学位。在高水平国际统计医学期刊以及图像模式识别顶会上发表学术论文40多篇,包括《Journal of the American Statistical Association》《Biometrika》《IEEE Transactions on Neural Networks and Learning Systems》《IEEE Transactions on Medical Image》《NeuroImage》《Medical Image Analysis. 研究方向包括生物统计,医学图像分析,函数数据分析,形状数据分析等。

【报告摘要】:Mediation analysis is an important tool in the imaging genetics study for Alzheimer's disease (AD), where the goal is to identify the causal mechanism or pathway that links the genetic exposures and neurological outcomes, through some neuroimaging mediators. Although various mediation analysis approaches have been proposed to discover the underlying causal pathway in AD, there are several challenges, such as the subgroup heterogeneities in terms of (i) brain connectomes and (ii) causal mechanisms. To address these issues, we propose a novel mediation analysis tool that can simultaneously detect individual brain connectomes and subgroup causal pathways. Specifically, a two-layer structure mixture model, including a mixture of conditional Gaussian graphical models, is developed to establish the heterogeneous mediation pathways. A penalized EM algorithm is proposed to estimate both the average direct effect and indirect effect. Both simulation studies and a real example using the diffusion tensor imaging data from the ADNI study are conducted to assess the finite sample performance of our method.

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