title: Bayesian Variable Selection in Multilevel Item Response Theory Models with Application in Genomics.
abstract: The goal of this paper is to present an implementation of stochastic search variable selection (SSVS) to multilevel model from item response theory (IRT). As experimental settings get more complex and models are required to integrate multiple (and sometimes massive) sources of information, a model that can jointly summarize and select the most relevant characteristics can provide better interpretation and a deeper insight into the problem. A multilevel IRT model recently proposed in the literature for modeling multifactorial diseases is extended to perform variable selection in the presence of thousands of covariates using SSVS. We derive conditional distributions required for such a task as well as an acceptance-rejection step that allows for the SSVS in high dimensional settings using a Markov Chain Monte Carlo algorithm. We validate the variable selection procedure through simulation studies, and illustrate its application on a study with genetic markers associated with the metabolic syndrome.
authors.affiliation: Department of Applied Mathematics and Statistics, ICMC-USP, Brazil.
authors.forename: Tiago M
authors.initials: TM
authors.lastname: Fragoso
authors.affiliation: Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Mariza
authors.initials: M
authors.lastname: de Andrade
authors.affiliation: Laboratory of Genetic and Molecular Cardiology, InCor-FMUSP, Brazil.
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
authors.affiliation: Department of Animal Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Guilherme J M
authors.initials: GJ
authors.lastname: Rosa
authors.affiliation: Department of Statistics, IME-USP, Brazil.
authors.forename: Júlia M P
authors.initials: JM
authors.lastname: Soler
mesh_terms: D000465:Algorithms; D001499:Bayes Theorem; D005819:Genetic Markers / Q000235:genetics; D023281:Genomics / Q000379:methods*; D006801:Humans; D008390:Markov Chains; D024821:Metabolic Syndrome / Q000235:genetics; D008957:Models, Genetic; D015233:Models, Statistical; D009010:Monte Carlo Method; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D013269:Stochastic Processes
chemical_list: D005819:Genetic Markers
keywords: MCMC; data augmentation; metabolic syndrome; stochastic search variable selection