st: Proportional hazard assumption

[Grethe Søndergaard <dkstatstata@gmail.com>]

Hi,

A while ago I asked you about your help regarding test of the
proportional hazard assumption when the stratas you include are very
small (2-6 individuals). I got some useful responses but I have got
two additional questions:

Question 1)
If the graph that this plot creates is horizontal will that indicate
that the proportional hazard assumption is met?
Stcox i.education, strata(stratum_variable) scaledsch(sca*) schoenfeld(sch*)
Stphtest, rank plot (i.education)

Question 2)
Age is the underlying time scale. I have tried to stsplit my data in
death (the outcome) before and after age 45 to test if there is a
better goodness of fit in the two age-specific models compared to the
full model. I would like to use "estimates store" and "lrtest" to do
this - but is this possible when I need to compare the full models
with the two age-specific models at the same time?

Thank you

Grethe
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