topic ERROR: Variable in the RANDOM statement has only one level. in SAS Programming

ERROR: Variable in the RANDOM statement has only one level.

fouke_o — Thu, 15 Jun 2023 15:12:50 GMT

Hi all,

I am trying to fit a frailty model in my survival analysis using this code:

PROC PHREG data=DataSurvival ;
CLASS Riluzol Center;
MODEL timeM*Deceased(0)=Riluzol ALSFRSRdecline Diagnosticdelay ;
RANDOM Center / noclprint;
HAZARDRATIO 'Frailty Model Analysis' Riluzol;
Format Center Sites.;
RUN;

And keep getting the error:
ERROR: Variable Center in the RANDOM statement has only one level.

My center variable for riluzol looks like this:

Table of Riluzol by CenterRiluzol Center1 2 3 4 Total01TotalFrequency Missing = 639

195 13.72	3 0.32	1030 35.99	181 12.46	1409
1226 86.28	926 99.68	1832 64.01	1272 87.54	5256
1421	929	2862	1453	6665

Anyone any idea?

Thanks!

Re: ERROR: Variable in the RANDOM statement has only one level.

PaigeMiller — Thu, 15 Jun 2023 15:20:30 GMT

Could you please re-format the table so I can read it and understand it? And also please explain what this table is and how it was created.

Re: ERROR: Variable in the RANDOM statement has only one level.

fouke_o — Thu, 15 Jun 2023 15:24:16 GMT

NIV users

The FREQ Procedure

Sorry, it did something with the table, here you go:

Re: ERROR: Variable in the RANDOM statement has only one level.

PaigeMiller — Thu, 15 Jun 2023 15:28:20 GMT

ERROR: Variable Center in the RANDOM statement has only one level.

When SAS says there is only one level, I believe SAS. It may be that because of missing values somewhere in your data set, the model winds up with only a single level of CENTER. Anyway, given the model you are fitting, we would need to see frequency tables on all variables in the model, not just the one you show.

Re: ERROR: Variable in the RANDOM statement has only one level.

ballardw — Thu, 15 Jun 2023 15:39:03 GMT

I think that you may want to examine a few more variables in combination. I think that you can get a message like that when considering the DEPENDENT variable(s) if there is only one value of the random variable associated with a given outcome.

You might try:

proc freq data=datasurvival;
  table deceased*Riluzol*center / list ;
run;

And see if a combination of deceased and riluzol only have one value of Center .

From your table I suspect Center=Tours and Riluzol=0 all have the same value for Deceased.