Am getting an MMRM as below   proc mixed data=weight;  class sex patid region; month  model chg=baseweight age sex region month month*base/ddfm=ken s;  repeated month/subject=patid type=un;  store out=meanweight; run;   I would like to make a prediction for chg for a month-outside the sample i.e month is 2 4 6 8 and I would like to make predictions for say month 10.   My approach was  proc plm restore=meanweight;   score data=null out=pred predicted lclm uclm/ilink; run;   null has a single observation with values for baseweight, sex, region, and month. The problem is that for any month value that is more than 8 ie max visit in study, I get missing predictions. Am I using this procedure wrongly? Kind regards W ... View more