Hello,

I'm trying to run a multilevel mixed effects survival model using the stmixed command, where students are nested in schools, which are then nested in districts. I've already declared the dataset as a survival data using stset.

stmixed lowincome female || district: || sch_id:, distribution(rp)

When I run the command above, I receive this error message:

independent variables are required when option noconstant is specified
r(102);

I'm not sure what this means. As you can see, I did not specify "no constant" option in the syntax. I thought "lowincome" and "female" are taken as independent variables/covariates in this situation.




I'd appreciate any suggestions!