frailtypack (version 2.7.1)

SurvIC: Create a survival object for interval censoring and possibly left truncated data

Description

This is a function used in case of interval-censoring as a response variable in a model formula only for Cox proportional hazard or shared frailty model. Sometimes, an unobserved event might occur in a time interval [L,U]. RecurrentAG argument gets invalid with the use of SurvIC. Time dependant variables are not allowed.

Usage

SurvIC(t0, lower, upper, event)

Arguments

t0

Truncation time for left truncated data only. To be ignored otherwise.

lower

Starting time of the interval for interval-censored data. Time of right-censoring instead.

upper

Ending time of the interval for interval-censored data. For right-censored data, lower and upper time must be equal (for numerical reason).

event

Status indicator 0=right-censored, 1=interval-censored

Details

Typical usages are SurvIC(lower,upper,event) or SurvIC(t0,lower,upper,event)

Examples

data(bcos)
bcos$event <- ifelse(bcos$left!=bcos$right,1,0)

###---  Cox proportional hazard model with interval censoring ---###

cox.ic <- frailtyPenal(SurvIC(left,right,event)~treatment,
data=bcos,n.knots=8,kappa=10000)

###---  Shared model with interval censoring ---###

bcos$group <- c(rep(1:20,4),1:14)

sha.ic <- frailtyPenal(SurvIC(left,right,event)~cluster(group)+
treatment,data=bcos,n.knots=8,kappa=10000)