Date:         Wed, 14 Oct 2009 13:07:08 -0500
Reply-To:     Robin R High <rhigh@UNMC.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Robin R High <rhigh@UNMC.EDU>
Subject:      Re: proc genmod - repeated measures
Comments: To: nuria <nchapinal@YAHOO.COM>
In-Reply-To:  <39c54bed-f584-4bd4-874c-5bdc4b8bf391@h14g2000pri.googlegroups.com>
Content-Type: text/plain; charset="US-ASCII"

Nuria,

With the type3 option on the MODEL statement along with a repeated
statement SAS computes a type3 table based on a "generalized score
statistic" (see p. 1993 of SAS/STAT documentation of GENMOD for
reference).  You can match the type3 pvalues and the GEE parameter
estimate table of pvalues [with two level class data or covariates] by
adding the wald option

MODEL ... / ... type3 wald;
REPEATED .. ;

Which one to interpret is not clear, though I would assume both need to
have reasonably large number of clusters (.. e.g. cows).

Robin High
UNMC





From:
nuria <nchapinal@YAHOO.COM>
To:
SAS-L@LISTSERV.UGA.EDU
Date:
10/14/2009 10:27 AM
Subject:
proc genmod - repeated measures
Sent by:
"SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>



Hi,

If I run a model like this, where treatment has only two categories

proc genmod ;
class cow treatmen;
model sickness = treatment/dist=binomial type3;
repeated subject=cow /type=cs;
run;

Do I need to look at the p-values for the type3 test or at Analysis Of
GEE Parameter Estimates? I found sometimes the p-values are similar,
but some other times aren't, and they may run into conflict.... for
instance, treatment could be significant only in one of the tests...

Thanks!