dynpred (version 0.1.2)

AUC: Calculate AUC(t) curve

Description

Calculate model-free curve of Area Under the Curve values over time, based on the dynamic/incident AUC of Heagerty and Zheng.

Usage

AUC(formula, data, plot = TRUE)

Arguments

formula

Formula for prediction model to be used as in coxph

data

Data set in which to interpret the formula

plot

Determines whether the AUC function should be plotted (if TRUE (default)) along with a lowess curve or not (if FALSE)

Value

A list with elements

AUCt

A data frame with time t in column time and AUC(t) in column AUC

AUC

The AUC(t) weighted by Y(t)-1, with Y(t) the number at risk at t; this coincides with Harrell's c-index

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.

Heagerty PJ & Zheng Y (2005), Survival model predictive accuracy and ROC curves, Biometrics 61, 92-105.

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

Examples

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