I am running a multi-state (Huggins) closed robust design with 8 groups, 2 strata, and 1 covariate. In the Enter specifications window, the mixtures choice is greyed out, but when I run a model it shows the following:
INPUT --- proc chmatrix occasions=12 groups=8 etype=HCRDMS mixtures=2
INPUT --- icovar=1 ICMeans strata=2 NoHist hist=626;
Why?
There are no mixture (pi) parameters in my PIMs. Do I need to be concerned that something is incorrect?