mets (version 0.2.8)

ipw: Inverse Probability of Censoring Weights

Description

Calculates Inverse Probability of Censoring Weights (IPCW) and adds them to a data.frame

Usage

ipw(formula, data, cluster, samecens = FALSE, obsonly = TRUE,
  weightname = "w", cens.model = "aalen", pairs = FALSE, ...)

Arguments

formula

Formula specifying the censoring model

data

data frame

cluster

clustering variable

samecens

For clustered data, should same censoring be assumed (bivariate probability calculated as mininum of the marginal probabilities)

obsonly

Return data with uncensored observations only

weightname

Name of weight variable in the new data.frame

cens.model

Censoring model (default Aalens additive model)

pairs

For paired data (e.g. twins) only the complete pairs are returned (With pairs=TRUE)

...

Additional arguments to censoring model

Examples

data(prt)
prtw <- ipw(Surv(time,status==0)~country, data=prt[sample(nrow(prt),5000),],
            cluster="id",weightname="w")
plot(0,type="n",xlim=range(prtw$time),ylim=c(0,1),xlab="Age",ylab="Probability")
count <- 0
for (l in unique(prtw$country)) {
    count <- count+1
    prtw <- prtw[order(prtw$time),]
    with(subset(prtw,country==l),
         lines(time,w,col=count,lwd=2))
}
legend("topright",legend=unique(prtw$country),col=1:4,pch=-1,lty=1)