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I take the canned data that is used to demonstrate the coxph function in R, and then I look at the cumulative hazard.

require(survival)
options(na.action=na.exclude) # retain NA in predictions
fit <- coxph(Surv(time, status) ~ age + ph.ecog + strata(inst), lung)
x <- basehaz(fit)
p <- x[x$strata=='inst=1',]$hazard
plot(p)

basehaz is reporting a cumulative hazard function that moves greater than 1.

cumulative hazard plot

How is this possible?

JoeBass
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1 Answers1

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The hazard function needs to be positive but it is not restricted to be smaller than 1.

Dimitris Rizopoulos
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