Hi everyone,

Below is an example from my dataset.

datediag dead dateexit id perdiag agegrp
4429 1 4706 1570110 0 5
4533 1 6754 1570111 0 5
4387 1 4650 1570112 1 5
4669 1 4856 1570113 0 4
4123 1 4236 1570114 0 3
4883 0 4896 1570115 0 2
4324 1 4432 1570116 0 5

I am stuck at a problem.

The exact problem is
“For the first three years since diagnosis, how can I estimate the effect of the age of diagnosis (variable agegroup) on the mortality rate among participants?”
I am doing the following

First, I have to use the stset command
stset dateexit, id(id) failure(dead==1) origin (time datediag) scale(365.25)

Secondly, I have to use stsplit command
stsplit yearsincediag, at (0 (1) 3)

Then, I use
stmh agegrp, by(yearsincediag)

Is this correct????
Should I use
Strate or stmh??

What’s the difference between strate and stmh????