topic Re: trend p-value using the Cochran-Armitage test in Statistical Procedures

trend p-value using the Cochran-Armitage test

fanuser — Wed, 12 Mar 2025 02:39:37 GMT

I have a simple dataset. Is it possible to obtain a p-value using the Cochran-Armitage test? The following is the table:

Group	Successes	Total Trials	Proportion
1	20	500	0.04
2	30	1000	0.03
3	40	500	0.08

Re: trend p-value using the Cochran-Armitage test

Ksharp — Wed, 12 Mar 2025 03:27:15 GMT

Yes. As long as your contingency table is 2xC or Rx2 , you can do Cochran-Armitage test.

But you need transform your data into this structure:

Re: trend p-value using the Cochran-Armitage test

fanuser — Wed, 12 Mar 2025 13:12:42 GMT

How can I restructure my data to match the format you mentioned? I don't have any additional information.
Thanks!

Re: trend p-value using the Cochran-Armitage test

SAS_Rob — Wed, 12 Mar 2025 13:18:10 GMT

You have all the information you need. You will just need to restructure your data set like the following:

data test;
input Group Successes Total;
cards; 
1 20 500 
2 30 1000
3 40 500
;
run;
data test2;
set test;
resp='y';ct=successes;output;
resp='n';ct=total-successes;output;
run;

proc freq data=test2 order=data;
weight ct;
tables resp*group/trend;
run;

Re: trend p-value using the Cochran-Armitage test

fanuser — Wed, 12 Mar 2025 13:30:12 GMT

Thank you very much for providing such a wonderful solution!