vardiffC {compareC}R Documentation

Variance estimation of the difference between two correlated overall C indices

Description

This is a function used to estimate the variance of the difference between two correlated overall C indices

Usage

	vardiffC(timeX, statusX, scoreY, scoreZ)

Arguments

timeX

The vector of actual survival time X, one survival time for each observation

statusX

The matching vector of event indicator for time X, 1 if occured and 0 otherwise

scoreY

The vector of the first measured biomarker Y, one for each of the same observations, based on which the variance of the difference in overall C indices is to be estimated

scoreZ

The vector of the second measured biomarker Z, one for each of the same observations, based on which the variance of the difference in overall C indices is to be estimated

Value

est.vardiff_c

The estimated variance of the difference of two C indices

est.varCxy

The estimated variance of the C index for scoreY

est.varCxz

The estimated variance of the C index for scoreZ

est.cov

The estimated covariance between the two C indices for scoreY and that for scoreZ

Author(s)

Le Kang, Weijie Chen

References

Harrell FE, Califf RM, Pryor DB, Lee KL, and Rosati RA. (1982) Evaluating the yield of medical tests. The Journal of the American Medical Association, 247(18), 2543–2546

Pencina MJ and D'Agostino RB. (2004) Overall C as a measure of discrimination in survival analysis: model specific population value and confidence interval estimation. Statistics in Medicine, 23(13), 2109–2123

Kang L, Chen W, Petrick NA, and Gallas BD. (2014) Comparing two correlated C indices with right-censored survival outcome: a one-shot nonparametric approach. Statistics in Medicine, 34(4), 685–703, doi: 10.1002/sim.6370

See Also

estC,compareC

Examples

demo(testC)

[Package compareC version 1.3.1 Index]