topic Re: Mixed Procedure in SAS Procedures

Mixed Procedure

k2k — Thu, 30 Oct 2014 15:39:39 GMT

Dear Sir/Madam

I am having doubt in Estimate Statement in proc mixed procedure.

ESTIMATE 'TEST VS REFERENCE' TRT 1 -1;

When want to use 1 -1 or -1 1,

TRT (T- Test and R- Reference) code as TRT -1 1 to compare test with reference. my results are matching, but for TRT (A- Test and B- Reference) I used same code but my results are not matching if we use 1 -1 then my answer is matching.

What logic is behind this?

Re: Mixed Procedure

PaigeMiller — Thu, 30 Oct 2014 16:45:46 GMT

What results don't match? Can you show us? (Also, the complete PROC MIXED code would be helpful)

Re: Mixed Procedure

k2k — Thu, 30 Oct 2014 17:21:42 GMT

Dear paigemiller,

SAS Proc mixed Code,

PROC MIXED DATA = PK;

CLASSES SEQUENCE SUBJECT PERIOD TRT;

MODEL LN_CMAX = SEQUENCE PERIOD TRT / ddfm = satterth;

RANDOM TRT / type = fa0(2) sub = SUBJECT G;

REPEATED/grp = TRT sub = SUBJECT;

LSMEANS TRT / cl alpha = 0.05 diff;

ESTIMATE 'T vs. R' TRT -1 1/cl alpha = 0.1;

ODS OUTPUT ESTIMATES = CMAXUNSCL ( keep = lower upper );

ODS OUTPUT LSMEANS = CMAXLSM

TESTS3 = CMAXTYPE3

COVPARMS = CMAXCPARMS

DIFFS = CMAXDIFF;

RUN;

90 % CI is not matching CI=exp(lower);

Re: Mixed Procedure

PaigeMiller — Thu, 30 Oct 2014 17:49:19 GMT

That really doesn't help. We can't see what the results are, we don't see what doesn't match, you need to SHOW US the non-matching output. And you also need to show us the two versions of the code that gives the non-matching output.

Re: Mixed Procedure

SteveDenham — Thu, 30 Oct 2014 19:46:26 GMT

So the 90% CI in the ESTIMATE block does not match 'lower' and 'upper' in the output dataset? That seems really unlikely, since it is an ODS dataset..

I have to echo here---show what does not match explicitly.

That particular piece of code has some interesting tricks going on, so it really makes a difference when you say things don't match that we be able to duplicate what you see.

Steve Denham