topic MMRM (proc mixed) in Statistical Procedures

MMRM (proc mixed)

_Hopper — Thu, 30 Jan 2025 18:05:47 GMT

prproc mixed data = admp ;
class subjid treatnp avisit agegr1 ;
model chg = treatnp base avisit treatnp*avisit agegr1;
repeated avisit / subject= subjid type=UN;
lsmeans treatnp / cl diff e;
ods output diffs = mmrmchgdiff estimates = mmrmchgest;
run;

1. How can you tell if the procedure converged other than the warnings it sends to the log?

2. Where can I find information on the variables and layout of the ODS table outputs generated by DIFFS, and ESTIMATES (or any ods table output from the procedure)?

3. Following (2) - I cannot recall if SE of the estimates and differences are generated automatically in those datasets. What options are required for an LS means analysis to do this?

Re: MMRM (proc mixed)

JackieJ_SAS — Thu, 30 Jan 2025 19:30:41 GMT

Hi, For your first question, have a look at this example in the documentation:
SAS Help Center: Repeated Measures

The Iteration History section tells you whether the model converged:

For your second question- this page in the documentation describes ODS table names and their variables:
SAS Help Center: ODS Table Names

I see that there are ODS tables named Diffs and Estimates, as you have in your code. Another easy way to figure out tables names is run the statement ODS TRACE ON; prior to your PROC MIXED code. With this, table names will be written to the log.

Your code looks ok. Is it providing output?

Re: MMRM (proc mixed)

Ksharp — Fri, 31 Jan 2025 02:24:38 GMT

1) Check Rick_SAS blog:
https://blogs.sas.com/content/iml/2019/04/03/g-matrix-is-not-positive-definite.html
2)Using the following code to check the ODS tables name (in LOG window):
ods trace on;
proc mixed ......
.......
run;
ods trace off;
3)Yes. If I was right. SE of the estimates and differences are generated automatically in OUTPUT.

Re: MMRM (proc mixed)

StatsMan — Fri, 31 Jan 2025 12:28:09 GMT

You can find a pretty good read on the convergence status table here . This in the shared concepts and topics section of the SAS/STAT documentation.

Re: MMRM (proc mixed)

_Hopper — Tue, 04 Feb 2025 14:12:58 GMT

Only in the list window. No ods tables are generated.

Re: MMRM (proc mixed)

JackieJ_SAS — Mon, 10 Feb 2025 19:53:05 GMT

Hi, Could you provide us a copy of your log and output, so that we can review your code and any notes and errors?