Cochran-Mantel-Haenszel test

On occasion you need to perform a test for association between two categorical variables while stratifying, or controlling, for a third variable. The Cochran-Mantel-Haenszel test for association stratifies by a third variable to give proper weight to strata size. In the previous example, let s assume that you want to stratify your analysis by center to control for differences in center size. You can then run a Cochran-Mantel-Haenszel test like this ... 

For Cochran-Mantel-Haenszel tests in PROC FREQ, you usually want to structure your TABLE statement in the following way ... 

The analytical approach to safety data is limited but growing (Dubey et al., 2006). Some suitable statistical techniques that can be employed include Fisher s exact test, the Mantel-Haenszel test, and the adapted Cochran-Mantel-Haenszel test, all of which can be used to compare adverse event rates between treatment groups (see Chow and Liu, 2004, for further details). 

The Cochran-Mantel-Haenszel (CMH) test contains three different tests for association. The following table describes each test and shows where the / -value can be found in your pvalue data set. 

The Cochran-Mantel-Haenszel (CMH) tests are a collection of procedures that extend the simple chi-squared tests introduced in Chapter 4 to incorporate the multicentre setting. Landis, Heyman and Koch (1978) provide further details. 

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