Handout05 Stat3900/4950



The first program has two new lines of code at the top that clears the log and 

the output files and renumbers the output starting at page 1 after you each run

of you SAS program.  The program is from page 80 in the Cody&Smith book and is

useful for running a Chi-Square test if the counts are given.



You should find a Chi-Square test problem in you introductory statistics book

and work out the details of the problem and then check your work by running this

program.



The next program is for computing the odds ratio for a case-control 

study and the last one is for computing the relative risk for a cohort

study.



odds = [p1/(1-p1)]/[p2/(1-p2)]



rr = p1/p2



With all three programs note that the weight subcommand of proc freq is used

since the summary table has already been computed and the results are used as 

the datalines.



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DM 'LOG;CLEAR;OUT;CLEAR';

OPTIONS PAGENO = 1 LINESIZE = 74 PAGESIZE = 64;



data chisq;

	n+1;

	do row = 1 to 2;

		do col = 1 to 2;

			input count @;

			output;

		end;

	end;

datalines;

10 20 30 40

;

proc freq data=chisq;

	tables row*col / chisq;

	weight count;

run;



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* Program to compute the Odds Ratio and the 95% CI;

data odds;

	input outcome $ exposure $ count;

datalines;

case 1-Yes 50

case 2-No 100

control 1-Yes 20

control 2-No 130

;

proc freq data=odds;

	title 'Program to compute an Odds Ratio';

	tables exposure*outcome / chisq cmh;

	weight count;

run;

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data rr;

	length group $ 9;

	input group $ outcome $ count;

datalines;

1-placebo mi 20

1-placebo no-mi 80

2-asprin mi 15

2-asprin no-mi 135

;

proc freq data=rr;

	title 'Program to compute a relative risk';

	tables group*outcome / CHM;

	weight count;

run;



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