Association Analysis for Count Data Using SAS

In SAS, association analysis methods for count data/contingency tables is typically performed using the PROC FREQ procedure. This procedure has options for Chi-Square and Fisher’s Exact tests.

Example: Lung Cancer Data

The following tabulation was used for the SAS Chi-Square and Fisher’s testing. This tabulation was derived from the same lung dataset used for the R function testing. The dataset is defined as follows:

data test_case; 
input treatment $ Count Weight $; 
datalines; 
Trt_A 22 0
Trt_B 39 0
Trt_A 39 1
Trt_B 113 1
; 

Tests of Association

The following SAS code produces both the Chi-Square and Fisher’s Exact tests of association. Note that the results contain many statistics not produced by the corresponding R function. The relevant sections of the output have been outlined in red.

proc freq data = test_case;
weight Count;
tables treatment * Weight / chisq fisher;
exact or;
run;

Output: