leuk {MASS} | R Documentation

## Survival Times and White Blood Counts for Leukaemia Patients

### Description

A data frame of data from 33 leukaemia patients.

### Usage

    data(leuk)

### Format

A data frame with columns:

`wbc`
  white blood count
`ag`
  a test result, `"present"` or `"absent"`
`time`
  survival time in weeks

### Source

Cox, D. R. and Oakes, D. (1984) Analysis of Survival Data, Chapman & Hall, p. 9. Taken from

Feigl, P. & Zelen, M. (1965) Estimation of exponential survival probabilities with concomitant information. Biometrics, 21, 826–838.

### Examples

    library(survival5)
    data(leuk)
    plot(survfit(Surv(time) ~ ag, data=leuk), lty=2:3, col=2:3)

    # now Cox models
    leuk.cox <- coxph(Surv(time) ~ ag + log(wbc), leuk)
    summary(leuk.cox)