Hi
I am a regular Stata user, but I'll also looking into solving problems in R. Here, I have problem I can't solve in Stata, but in R. Does anyone know how to do this in Stata?

Those are equal commands:

Code:
   stcox sex_rf i.bsi, strata(timeband)
Code:
fit <- coxph(Surv(t0,t, event==1) ~ sex_rf
                        +bsi_active +strata(timeband), data=data )

However, according to this article (subchapter "Step function to explore time-varying coefficient"), I would like to fit something accoring to


Code:
fit <- coxph(Surv(t0,t, event==1) ~ sex_rf
                        +bsi_active:strata(timeband), data=data )
Is there a way to do this in Stata as well?