title: A generalized Kruskal-Wallis test incorporating group uncertainty with application to genetic association studies.
abstract: Motivated by genetic association studies of SNPs with genotype uncertainty, we propose a generalization of the Kruskal-Wallis test that incorporates group uncertainty when comparing k samples. The extended test statistic is based on probability-weighted rank-sums and follows an asymptotic chi-square distribution with k - 1 degrees of freedom under the null hypothesis. Simulation studies confirm the validity and robustness of the proposed test in finite samples. Application to a genome-wide association study of type 1 diabetic complications further demonstrates the utilities of this generalized Kruskal-Wallis test for studies with group uncertainty. The method has been implemented as an open-resource R program, GKW.
authors: Department of Statistics, University of Toronto, Ontario, Canada. elif.acar@ad.umanitoba.ca
authors: Elif F
authors: EF
authors: Acar
authors: Lei
authors: L
authors: Sun
mesh_terms: D001699:Biometry / Q000379:methods*; D016009:Chi-Square Distribution; D003198:Computer Simulation; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000235:genetics; D056726:Genetic Association Studies / Q000706:statistics & numerical data*; D005838:Genotype; D006801:Humans; D015233:Models, Statistical; D020641:Polymorphism, Single Nucleotide; D018709:Statistics, Nonparametric; D035501:Uncertainty