SAS Textbook Examples
An Introduction to Categorical Analysis by Alan
Agresti
Chapter 9 – Models for Matched Pairs
9.1 Comparing Dependent Proportions
9.1.1 McNemar Test
In SAS proc freq we can request McNemar test by using option agree after the tables statement. Notice that in the book the McNemar test is done in terms of z-statistic, while in SAS it is done as a chi-square statistic.
data rating; input rating1 rating2 count; cards; 1 1 794 1 0 150 0 1 86 0 0 570 ; run; proc freq data = rating; weight count; tables rating1*rating2 /agree; run;
The FREQ Procedure
Table of rating1 by rating2
rating1 rating2
Frequency|
Percent |
Row Pct |
Col Pct | 0| 1| Total
---------+--------+--------+
0 | 570 | 86 | 656
| 35.63 | 5.38 | 41.00
| 86.89 | 13.11 |
| 79.17 | 9.77 |
---------+--------+--------+
1 | 150 | 794 | 944
| 9.38 | 49.63 | 59.00
| 15.89 | 84.11 |
| 20.83 | 90.23 |
---------+--------+--------+
Total 720 880 1600
45.00 55.00 100.00
Statistics for Table of rating1 by rating2
McNemar's Test
------------------------
Statistic (S) 17.3559
DF 1
Pr > S <.0001
Simple Kappa Coefficient
--------------------------------
Kappa 0.6996
ASE 0.0180
95% Lower Conf Limit 0.6644
95% Upper Conf Limit 0.7348
Sample Size = 1600
9.1.2 Estimating Differences of Proportions
9.2 Logistic Regression for Matched Pairs
9.2.1 Connection between McNemar and Cochran-Mantel-Haenszel Tests