Dear All, I'm trying to run a model on a subset of my data identified by year = 2002. Does anyone know whats wrong with the syntax below: glmmPQL(desm~desdat,random=~1|male,family=quasibinomial, data=mcare,subset=year=2002) I get an error message all the time, but it worked with string variables (like: subset=sex=="M"). Thanks, Istvan