YSPH Biostatistics Seminar: “Semiparametric Modeling Methods for Environmental Mixtures"

NOTE: You are invited to attend in person, but may also attend via Zoom.

SPEAKER: Myeonggyun (Matt) Lee, PhD, Postdoctoral Fellow, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences

TITLE: “Semiparametric Modeling Methods for Environmental Mixture"

ABSTRACT: Humans are exposed to diverse chemical and non-chemical exposures throughout their lives. Understanding the impact of environmental mixtures instead of individual effects on human health is of great interest. However, environmental mixture studies face several challenges, including high-dimension, high correlation among health and exposure measures, nonlinear response curve and complex interactions. In this talk, we aim to address these challenges by exploring semiparametric modeling methods. Firstly, we developed partial-linear single-index (PLSI) models that consist of a single index of exposures with practical interpretability, and a nonparametric link function for modeling flexibility. We specifically focused on PLSI models for time-to-event outcomes, which can accommodate multiple correlated time-dependent covariates. We further developed a multiple-index interaction model (MIIM), which extended the PLSI framework to allow indices corresponding to exposure natural groupings and their pairwise interactions. We assessed the performance of our proposed methods through simulation studies and demonstrated their applications using real data from the World Trade Center (WTC)-exposed Fire Department of the City of New York (FDNY) cohort study, investigating the impact of metabolic syndrome on the risk of developing WTC lung injury, and the National Health and Nutrition Examination Survey (NHANES) data to understand how persistent organic pollutants (POPs) influence leukocyte telomere length.

YSPH values inclusion and access for all participants. If you have questions about accessibility or would like to request an accommodation, please contact Charmila Fernandes at Charmila.fernandes@yale.edu. We will try to provide accommodations requested by December 13, 2023.