rcorrp.cens {Hmisc} | R Documentation

## Rank Correlation for Paired Predictors with a Censored Response

### Description

Computes U-statistics to test for whether predictor X1 is more concordant than predictor X2, extending rcorr.cens. For method=1, estimates the fraction of pairs for which the x1 difference is more impressive than the x2 difference. For method=2, estimates the fraction of pairs for which x1 is concordant with S but x2 is not.

### Usage

    rcorrp.cens(x1, x2, S, outx=FALSE, method=1)

### Arguments

`x1` | first predictor
`x2` | second predictor
`S` | a possibly right-censored `Surv` object. If `S` is a vector instead, it is converted to a `Surv` object and it is assumed that no observations are censored.
`outx` | set to T to exclude pairs tied on x1 or x2 from consideration
`method` | see above

### Value

a vector of statistics

### Author(s)

Frank Harrell
Department of Biostatistics, Vanderbilt University
f.harrell@vanderbilt.edu

### See Also

`rcorr.cens`, `somers2`, `Surv`

### Examples

    set.seed(1)
    if(.R.) library(survival)
    x1 <- rnorm(400)
    x2 <- x1 + rnorm(400)
    d.time <- rexp(400) + (x1 - min(x1))
    cens   <- runif(400,.5,2)
    death  <- d.time <= cens
    d.time <- pmin(d.time, cens)
    rcorrp.cens(x1, x2, Surv(d.time, death))
    # rcorrp.cens(x1, x2, y) ## no censoring

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