stCPE {SurvEval}

Estimate the Durability of a Baseline Risk Score or the CPE for a Fixed Follow-up Duration.

Description

This implements the methodology developed by Devlin, Gonen, and Heller (2020) to estimate the durability of a baseline risk score estimated under a Cox proportional hazards model. The same methodology can be used to estimate the concordance probability estimate (CPE) up to a fixed follow-up duration in a study.

Usage

stCPE(Time, Event, Markers, starttime, tau)
 

Arguments

Time

Survival Time.

Event

Event Status.

Markers

A vector or matrix of covariates.

starttime

The start time when evaluating the durability of a risk score. This should be set to 0 when evaluating the CPE up to a study's follow-up duration.

tau

The end time under evaluation.

Details

This function implements the method described in Devlin, Gonen, and Heller (2020).

Value

an object with the following element

stCPE.estimate

which is the concordance probability estimate.

References

Devlin, Sean M., Mithat Gonen, and Glenn Heller. Measuring the temporal prognostic utility of a baseline risk score. Lifetime data analysis (2020).

Examples

SM0 = rnorm(300, 0,1)
SM1 = rnorm(300, 0,1)
NM0 = rnorm(300, 0,1)
NM1 = rnorm(300, 0,1)
  
S1 <- exp(-1*(0.408*SM0 +0.15*SM1 + 0.684*NM0+0.15*NM1))*rweibull(300,scale = 1 , shape=1) 
C1 <- runif(300, 0,1.58)
  
Time <- pmin(S1, C1)
Event <- 1*(S1 < C1)
 
Markers <- cbind(SM0,SM1,NM0 ,NM1 )
tau <- max(Time[Event==1])

stCPE(Time, Event, Markers, 0, tau)