***********************************************************************
* This is a program that illustrates the use of PROC FREQ for         *
* conducting a Mantel-Haenszel test within the setting of a multi-    *
* center clinical trial.                                              *
***********************************************************************;

proc format;
value centfmt  1='Phoenix'
               2='Denver'
               3='Miami'
               4='New York'
               5='Atlanta'
               6='Chicago';
value groupfmt 0='Placebo'
               1='Treatment';
value respfmt  0='Failure'
               1='Success';
run;

data one;
input center group response count;
format center centfmt. group groupfmt. response respfmt.;
cards;
1 0 0 24
1 0 1  8
1 1 0 20
1 1 1 12
2 0 0 44
2 0 1 28
2 1 0 40
2 1 1 32
3 0 0 25
3 0 1  5
3 1 0 20
3 1 1 10
4 0 0 14
4 0 1 16
4 1 0 12
4 1 1 18
5 0 0 32
5 0 1 20
5 1 0 24
5 1 1 28
6 0 0 45
6 0 1  5
6 1 0 32
6 1 1 18
;
run;

proc freq data=one;
tables center*group*response/cmh;
exact comor;
weight count;
title "Example of the Mantel-Haenszel Test Applied to a Multi-Center Trial";
run;