sim.cox: Simulation of output from Cox model.

In mets: Analysis of Multivariate Event Times

Simulation of output from Cox model.

Description

Simulates data that looks like fit from Cox model. Censor data automatically for highest value of the event times by using cumulative hazard.

Usage

sim.cox(cox,n,data=NULL,cens=NULL,rrc=NULL,entry=NULL,...)

Arguments

cox	output form coxph or cox.aalen model fitting cox model.
n	number of simulations.
data	to extract covariates for simulations (draws from observed covariates).
cens	specifies censoring model, if "is.matrix" then uses cumulative hazard given, if "is.scalar" then uses rate for exponential, and if not given then takes average rate of in simulated data from cox model.
rrc	possible vector of relative risk for cox-type censoring.
entry	delayed entry variable for simulation.
...	arguments for rchaz, for example entry-time

Author(s)

Thomas Scheike

Examples

data(sTRACE)
cox <-  coxph(Surv(time,status==9)~vf+chf+wmi,data=sTRACE)
sim1 <- sim.cox(cox,1000,data=sTRACE)
cc <- coxph(Surv(time,status)~vf+chf+wmi,data=sim1)
cbind(cox$coef,cc$coef)

cor(sim1[,c("vf","chf","wmi")])
cor(sTRACE[,c("vf","chf","wmi")])

cox <-  phreg(Surv(time, status==9)~vf+chf+wmi,data=sTRACE)
sim3 <- sim.cox(cox,1000,data=sTRACE)
cc <-  phreg(Surv(time, status)~vf+chf+wmi,data=sim3)
cbind(cox$coef,cc$coef)
plot(cox,se=TRUE)
plot(cc,add=TRUE,col=2)

cox <-  phreg(Surv(time,status==9)~strata(chf)+vf+wmi,data=sTRACE)
sim3 <- sim.cox(cox,100,data=sTRACE)
cc <-   phreg(Surv(time, status)~strata(chf)+vf+wmi,data=sim3)
cbind(cox$coef,cc$coef)
plot(cox)
plot(cc,add=TRUE,col=2)

mets documentation built on May 29, 2024, 3:51 a.m.