Bootstrap function in multi-state models
A generic nonparametric bootstrapping function for multi-state models.
msboot(theta, data, B = 5, id = "id", verbose = 0, ...)
theta |
A function of |
data |
An object of class 'msdata', such as output from
|
B |
The number of bootstrap replications; the default is taken to be quite small (5) since bootstrapping can be time-consuming |
id |
Character string indicating which column identifies the subjects to be resampled |
verbose |
The level of output; default 0 = no output, 1 = print the replication |
... |
Any further arguments to the function |
The function msboot samples randomly with replacement subjects from
the original dataset data. The individuals are identified with
id, and bootstrap datasets are produced by concatenating all selected
rows.
Matrix of dimension (length of output of theta) x B, with b'th column being the value of theta for the b'th bootstrap dataset
Marta Fiocco, Hein Putter <H.Putter@lumc.nl>
Fiocco M, Putter H, van Houwelingen HC (2008). Reduced-rank proportional hazards regression and simulation-based prediction for multi-state models. Statistics in Medicine 27, 4340–4358.
tmat <- trans.illdeath()
data(ebmt1)
covs <- c("score","yrel")
msebmt <- msprep(time=c(NA,"rel","srv"),status=c(NA,"relstat","srvstat"),
data=ebmt1,id="patid",keep=covs,trans=tmat)
# define a function (this one returns vector of regression coef's)
regcoefvec <- function(data) {
cx <- coxph(Surv(Tstart,Tstop,status)~score+strata(trans),
data=data,method="breslow")
return(coef(cx))
}
regcoefvec(msebmt)
set.seed(1234)
msboot(theta=regcoefvec,data=msebmt,id="patid")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.