survcomp (version 1.22.0)

hr.comp: Function to statistically compare two hazard ratios

Description

This function compares two hazard ratios from their betas and standard errors as computed by a Cox model for instance. The statistical test is a Student t test for dependent samples. The two hazard ratios must be computed from the same survival data.

Usage

hr.comp(hr1, hr2)

Arguments

hr1

first hazard ratio.

hr2

second hazard ratio.

Value

p.value

p-value from the Student t test for the comparison beta1 > beta2 (equivalently hr1 > hr2)

hr1

value of the first hazard ratio

hr2

value of the second hazard ratio

Details

The two hazard ratios must be computed from the same samples (and corresponding survival data). The function uses a Student t test for dependent samples.

References

Student 1908) "The Probable Error of a Mean", Biometrika, 6, 1, pages 1--25. Haibe-Kains, B. and Desmedt, C. and Sotiriou, C. and Bontempi, G. (2008) "A comparative study of survival models for breast cancer prognostication based on microarray data: does a single gene beat them all?", Bioinformatics, 24, 19, pages 2200--2208.

See Also

coxph, t.test

Examples

require(survival)
set.seed(12345)
age <- as.numeric(rnorm(100, 50, 10) >= 50)
size <- as.numeric(rexp(100,1) > 1)
stime <- rexp(100)
cens <- runif(100,.5,2)
sevent <- as.numeric(stime <= cens)
stime <- pmin(stime, cens)
hr1 <- hazard.ratio(x=age, surv.time=stime, surv.event=sevent)
hr2 <- hazard.ratio(x=size, surv.time=stime, surv.event=sevent)
hr.comp(hr1=hr1, hr2=hr2)