如何正确运用χ^(2)检验——三种R×C列联表资料的CMH χ^(2)检验

How to useχ^(2) test correctly——CMHχ^(2) tests for the data collected from the three kinds of R×C contingency tables

本文目的是介绍三种R×C列联表资料的CMH χ^(2)检验以及SAS软件实现的方法。第一种是"双向无序R×C列联表资料",与这种资料对应的CMH χ^(2)检验在本质上就是Pearson’s χ^(2)检验;第二种是"结果变量为有序变量的R×C列联表资料",与这种资料对应的CMH χ^(2)检验在本质上就是秩和检验;第三种是"双向有序且属性不同R×C列联表资料",与这种资料对应的CMH χ^(2)检验在本质上就是Pearson’s相关分析或Spearman’s秩相关分析。当R×C列联表资料中有1个或2个"有序变量"时,进行统计分析之前,需要给有序变量"赋值或评分"。在SAS/STAT的FREQ过程中,有四种评分方法。评分方法不同,CMH χ^(2)检验统计量的表达形式和计算结果都会发生相应变化。

The purpose of this paper was to introduce the CMHχ^(2) test and SAS software implementation of the three kinds of R×C contingency table data.The first type was called"two-way unordered R×C contingency table data".The CMHχ^(2) test corresponding to this type of data was essentially the Pearson’sχ^(2) test.The second type was called"R×C contingency table data with an ordinal outcome variable".The CMHχ^(2) test corresponding to this kind of data was essentially a rank sum test.The third type was called"R×C contingency table data which was of two ordinal variables with different attributes".The CMHχ^(2) test corresponding to the data was essentially Pearson’s correlation analysis or Spearman’s rank correlation analysis.When there were 1 or 2"ordinal variables"in the R×C contingency table data,it was necessary to"assign or score"the ordinal variables before performing statistical analysis.In the FREQ procedure of SAS/STAT,there were four scoring methods.With different scoring approach,both the expression form and the calculation results of CMHχ^(2) test statistics could change accordingly.