Simulation of Piecewise constant hazard models with two causes (Cox).

Simulates data from piecwise constant baseline hazard that can also be of Cox type. Censor data at highest value of the break points for either of the cumulatives.

Usage

rcrisk(
  cumhaz1,
  cumhaz2,
  rr1,
  rr2,
  n = NULL,
  cens = NULL,
  rrc = NULL,
  extend = TRUE,
  ...
)

Arguments

cumhaz1: cumulative hazard of cause 1
cumhaz2: cumulative hazard of cause 1
rr1: number of simulations or vector of relative risk for simuations.
rr2: number of simulations or vector of relative risk for simuations.
n: number of simulation if rr not given
cens: to censor further , rate or cumumlative hazard
rrc: retlativ risk for censoring.
extend: to extend the cumulative hazards to largest end-point
...: arguments for rchaz

Author

Thomas Scheike

Examples

data(bmt); 
cox1 <- phreg(Surv(time,cause==1)~tcell+platelet,data=bmt)
cox2 <- phreg(Surv(time,cause==2)~tcell+platelet,data=bmt)

X1 <- bmt[,c("tcell","platelet")]
n <- 100
xid <- sample(1:nrow(X1),n,replace=TRUE)
Z1 <- X1[xid,]
Z2 <- X1[xid,]
rr1 <- exp(as.matrix(Z1) %*% cox1$coef)
rr2 <- exp(as.matrix(Z2) %*% cox2$coef)

d <-  rcrisk(cox1$cum,cox2$cum,rr1,rr2)
dd <- cbind(d,Z1)

scox1 <- phreg(Surv(time,status==1)~tcell+platelet,data=dd)
scox2 <- phreg(Surv(time,status==2)~tcell+platelet,data=dd)
par(mfrow=c(1,2))
plot(cox1); plot(scox1,add=TRUE)
plot(cox2); plot(scox2,add=TRUE)

cbind(cox1$coef,scox1$coef,cox2$coef,scox2$coef)
#>                [,1]       [,2]       [,3]       [,4]
#> tcell    -0.4232606 -1.3189693  0.3991068  0.9335182
#> platelet -0.5654438 -0.6322906 -0.2461474 -0.4338470