sim.cause.cox: Simulation of cause specific from Cox models.

In mets: Analysis of Multivariate Event Times

Simulation of cause specific from Cox models.

Description

Simulates data that looks like fit from cause specific Cox models. Censor data automatically. When censoring is given in the list of causes this will give censoring that looks like the data. Covariates are drawn from data-set with replacement. This gives covariates like the data.

Usage

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

Arguments

coxs	list of cox models.
n	number of simulations.
data	to extract covariates for simulations (draws from observed covariates).
cens	specifies censoring model, if NULL then only censoring for each cause at end of last event of this type. 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. But censoring can also be given as a cause.
rrc	possible vector of relative risk for cox-type censoring.
...	arguments for rchaz, for example entry-time

Author(s)

Thomas Scheike

Examples

nsim <- 100

data(bmt)
# coxph          
cox1 <- coxph(Surv(time,cause==1)~tcell+platelet,data=bmt)
cox2 <- coxph(Surv(time,cause==2)~tcell+platelet,data=bmt)
coxs <- list(cox1,cox2)
dd <- sim.cause.cox(coxs,nsim,data=bmt)
scox1 <- coxph(Surv(time,status==1)~tcell+platelet,data=dd)
scox2 <- coxph(Surv(time,status==2)~tcell+platelet,data=dd)
cbind(cox1$coef,scox1$coef)
cbind(cox2$coef,scox2$coef)

data(bmt)
cox1 <- phreg(Surv(time,cause==1)~tcell+platelet,data=bmt)
cox2 <- phreg(Surv(time,cause==2)~tcell+platelet,data=bmt)
coxs <- list(cox1,cox2)
dd <- sim.cause.cox(coxs,nsim,data=bmt)
scox1 <- phreg(Surv(time,status==1)~tcell+platelet,data=dd)
scox2 <- phreg(Surv(time,status==2)~tcell+platelet,data=dd)
cbind(cox1$coef,scox1$coef)
cbind(cox2$coef,scox2$coef)
par(mfrow=c(1,2))
plot(cox1); plot(scox1,add=TRUE); 
plot(cox2); plot(scox2,add=TRUE); 

cox1 <- phreg(Surv(time,cause==1)~strata(tcell)+platelet,data=bmt)
cox2 <- phreg(Surv(time,cause==2)~strata(tcell)+platelet,data=bmt)
coxs <- list(cox1,cox2)
dd <- sim.cause.cox(coxs,nsim,data=bmt)
scox1 <- phreg(Surv(time,status==1)~strata(tcell)+platelet,data=dd)
scox2 <- phreg(Surv(time,status==2)~strata(tcell)+platelet,data=dd)
cbind(cox1$coef,scox1$coef)
cbind(cox2$coef,scox2$coef)
par(mfrow=c(1,2))
plot(cox1); plot(scox1,add=TRUE); 
plot(cox2); plot(scox2,add=TRUE); 

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