It turns out that the issue is ties in survival times. Repeating the data
produces tied failure times; weighting does not, so you get different results.
The effect is unusually large here, perhaps because of the small sample size.
If you use the (less accurate) Breslow correction for ties, yo
I am confuse by the results of the weights option for coxph. I
replicated each row three times from the help page for coxph in the
data frame test_freq. I had expected that the coefficients,
significance tests, and tests of non-proportionality would yield the
same results for the replicated and
2 matches
Mail list logo
