--- begin included message ---
But If I do
fit <- coxph(Surv(futime, fustat) ~ resid.ds *rx + ecog.ps, data = ovarian,
subset=ovarian$age>50)
anova(fit)
fit2 <- coxph(Surv(futime, fustat) ~ resid.ds +rx + ecog.ps, data=ovarian,
subset=ovarian$age>50)
anova(fit2,fit)
The first p-value seems to be wrong.
Would anybody please explain to me why?
Cheers,
Oscar
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The p-value seems wrong because it is wrong. You've found a bug in the
survival package.
(It has to do with missing values, and the attempt of anova.coxph to ensure that it does
not fit a sequence of models such that an observation is dropped partway through the list.)
Terry Therneau
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