compareC: Testing the difference between two correlated overall _C_...

In compareC: Compare Two Correlated C Indices with Right-Censored Survival Outcome

Testing the difference between two correlated overall C indices

Description

This is a function used to test if the difference in two correlated overall C indices is statistically significant

Usage

	compareC(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 or score Y, one for each of the same observations
scoreZ	The vector of the second measured biomarker or score Z, one for each of the same observations

Value

est.c	The estimated two C indices
est.diff_c	The estimated difference of the two C indices, i.e.,C_{XY}-C_{XZ}
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
zscore	Z score (test statistic) for hypothesis testing
pval	P value for the comparison of two C indices

Note

Under non-random censoring, the returned p-value is statistically invalid as the assumption of random censoring is violated.

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,vardiffC

Examples

demo(testC)

compareC documentation built on April 26, 2022, 9:06 a.m.