cindex {dynpred}

Calculate Harrell's c-index

Description

This function calculates Harrell's c-index.

Usage

cindex(formula, data)

Arguments

formula

Formula for prediction model to be used as in coxph

data

Data set in which to interpret the formula

Value

A list with elements

concordant

The number of concordant pairs

total

The total number of pairs that can be evaluated

cindex

Harrell's c-index

Author(s)

Hein Putter [e-mail]

References

Harrell FE, Lee KL & Mark DB (1996), Multivariable prognostic models: issues in developing models, evaluating assumptions and adequacy, and measuring and reducing errors, Statistics in Medicine 15, 361-387.

van Houwelingen HC, Putter H (2012). Dynamic Prediction in Clinical Survival Analysis. Chapman & Hall.

Examples

data(ova)
cindex(Surv(tyears, d) ~ Karn + Broders + FIGO + Ascites + Diam, data = ova)