svykm {survey}R Documentation

Estimate survival function.

Description

Estimates the survival function using a weighted Kaplan-Meier estimator. Standard errors are not currently available.

Usage

svykm(formula, design,se=FALSE, ...)
## S3 method for class 'svykm':
plot(x,xlab="time",ylab="Proportion surviving",
  ylim=c(0,1),ci=NULL,lty=1,...)
## S3 method for class 'svykm':
lines(x,xlab="time",type="s",ci=FALSE,lty=1,...)
## S3 method for class 'svykmlist':
plot(x, pars=NULL, ci=FALSE,...)
## S3 method for class 'svykm':
quantile(x, probs=c(0.75,0.5,0.25),...)
## S3 method for class 'svykm':
confint(object,parm,level=0.95,...)

Arguments

formula Two-sided formula. The response variable should be a right-censored Surv object
design survey design object
se Compute standard errors? This is slow for moderate to large data sets
... in plot and lines methods, graphical parameters
x a svykm or svykmlist object
xlab,ylab,ylim,type as for plot
lty Line type, see par
ci Plot the confidence interval
pars A list of vectors of graphical parameters for the separate curves in a svykmlist object
object A svykm object
parm vector of times to report confidence intervals
level confidence level
probs survival probabilities for computing survival quantiles (note that these are the complement of the usual quantile input

Value

For svykm, an object of class svykm for a single curve or svykmlist for multiple curves.

See Also

svycoxph

Examples

data(pbc, package="survival")
pbc$randomized <- with(pbc, !is.na(trt) & trt>0)
biasmodel<-glm(randomized~age*edema,data=pbc)
pbc$randprob<-fitted(biasmodel)

dpbc<-svydesign(id=~1, prob=~randprob, strata=~edema, data=subset(pbc,randomized))

s1<-svykm(Surv(time,status>0)~1, design=dpbc)
s2<-svykm(Surv(time,status>0)~I(bili>6), design=dpbc)

plot(s1)
plot(s2)
plot(s2, lwd=2, pars=list(lty=c(1,2),col=c("purple","forestgreen")))

quantile(s1, probs=c(0.9,0.75,0.5,0.25,0.1))

s3<-svykm(Surv(time,status>0)~I(bili>6), design=dpbc,se=TRUE)
plot(s3[[2]],col="purple")

confint(s3[[2]], 365*(1:5))


[Package survey version 3.13 Index]