Cox proportional hazards assumption and boostrapp

[Al Bothwell]

I run a cox proportional hazards model with bootstrap. After this I tested the proportional assumption using estat phtest. Does estat phtest recognize the bootstrap replications? Here is my code:

stcox i.intensive i.album_cat i.bmi_cat i.statin i.aspirin, vce(bootstrap, nodots reps(1000) seed(5000)) cformat(%9.2f) pformat(%5.2f) sformat(%8.3f)
estat phtest

[Andrea Discacciati]

estat phtest will use the variance-covariance matrix ($Var(\hat{\beta})$) estimated using the bootstrap, if that's what you mean.
See formulas on page 117 here https://www.stata.com/manuals/st.pdf

[Al Bothwell]

Thank you. That is exactly what I wanted to clarify.