coxphQuantile {clinfun}R Documentation

Survival time quantile as a function of covariate

Description

Drwas a quantile curve of survival distribution as a function of covariate.

Usage

  coxphQuantile(phfit, xrange, p=0.5, whichx=1, otherx=NULL, ngrid=256, ...)

Arguments

phfit output from a proportional hazards fit.
xrange the range of covariate values for which the quantiles of survival times are computed.
p the probability level for the quantile (default is median).
whichx if there are more than one covariates in the Cox model, the one chosen for the quantile plot.
otherx the values for other covariates in the Cox model. If missing uses their average values.
ngrid number of points at which quantile is calculated.
... additional parameters to be passed on to the lines command.

Details

This function is used to draw quantile curves and has no output.

References

Heller G. and Simonoff J.S. (1992) Prediction in censored survival data: A comparison of the proportional hazards and linear regression models. Biometrics 48, 101-115.

Examples

## Not run: 
 library(survival)
  data(pbc)
  pbcfit <- coxph(Surv(time, status) ~ trt + log(copper), pbc,
    subset=(trt>0 & copper>0)) 
  plot(log(pbc$copper[pbc$trt>0 & pbc$copper>0]), pbc$time[pbc$trt>0 &
    pbc$copper>0], pch=c("o","x")[1+pbc$status[pbc$trt>0 & pbc$copper>0]], 
    xlab="log Copper", ylab="Survival time")
  coxphQuantile(pbcfit, c(2.5,6), whichx=2, otherx=1)
  coxphQuantile(pbcfit, c(2.5,6), p=0.75, whichx=2, otherx=2, col=2)
## End(Not run)

[Package clinfun version 0.7-1 Index]