Acar Elif F, Sun Lei
Department of Statistics, University of Toronto, Ontario, Canada.
Biometrics. 2013 Jun;69(2):427-35. doi: 10.1111/biom.12006. Epub 2013 Feb 26.
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.
受具有基因型不确定性的单核苷酸多态性（SNP）基因关联研究的启发，我们提出了Kruskal-Wallis检验的一种推广方法，该方法在比较k个样本时纳入了组不确定性。扩展的检验统计量基于概率加权秩和，在原假设下服从自由度为k - 1的渐近卡方分布。模拟研究证实了所提出检验在有限样本中的有效性和稳健性。将其应用于1型糖尿病并发症的全基因组关联研究，进一步证明了这种广义Kruskal-Wallis检验在具有组不确定性研究中的实用性。该方法已作为开源R程序GKW实现。
