topic Re: Proc freq for 7x2 table, significant; how to pairwise in SAS Procedures

Proc freq for 7x2 table, significant; how to pairwise

fengyuwuzu — Tue, 26 Apr 2016 16:26:42 GMT

I have age, gender (M,F) and sites (1,2,...7) columns, and I used proc freq to test (sites, gender ) and it showed p<0.001.

proc freq data= demo_sites ;
tables gender*sites_signup /chisq;
run;

But, how to do a pairwised chi-square test? I want to see which two groups are signigicant, and which two are not.

can I use proc multtest in this case?

A similar question for testing means of age in the 7 sites groups. I can use proc anova or proc glm to do a ANOVA test.

Is the solution to use proc multtest and contrast statement, like http://www.ats.ucla.edu/stat/sas/library/multtest.htm?

Re: Proc freq for 7x2 table, significant; how to pairwise

Astounding — Tue, 26 Apr 2016 16:32:43 GMT

This isn't an exact answer, but it may be helpful. Similar to CHISQ, there is an option (CELLCHISQ? may need to check my spelling) that adds to each cell its contribution to the overall chi-square.

Re: Proc freq for 7x2 table, significant; how to pairwise

fengyuwuzu — Tue, 26 Apr 2016 16:40:56 GMT

Thank you!! it is CELLCHI2.

With your hints I found one example:

http://support.sas.com/documentation/cdl/en/procstat/63104/HTML/default/viewer.htm#procstat_freq_sect030.htm

Thank you again!

Re: Proc freq for 7x2 table, significant; how to pairwise

SteveDenham — Tue, 26 Apr 2016 18:03:55 GMT

Regarding the testing of means, the LSMEANS statement in PROC GLM provides all of the options you need to compare all means in as many ways as you can think of, and adjust for the multiple comparisons using several methods.

proc glm data=yourdata;
class site;
model age=site;
lsmeans site/pdiff stderr cl adjust=sidak;
run;

This gives a Sidak adjustment for the 21 comparisons possible between the mean ages at the 7 sites.

Steve Denham

Re: Proc freq for 7x2 table, significant; how to pairwise

fengyuwuzu — Tue, 26 Apr 2016 19:35:28 GMT

@SteveDenham Yes! This works excellently!