nwtco: Data from the National Wilm's Tumor Study

In survival: Survival Analysis

Data from the National Wilm's Tumor Study

Description

Measurement error example. Tumor histology predicts survival, but prediction is stronger with central lab histology than with the local institution determination.

Usage

nwtco

Format

A data frame with 4028 observations on the following 9 variables.

seqno

id number

instit

Histology from local institution

histol

Histology from central lab

stage

Disease stage

study

study

rel

indicator for relapse

edrel

time to relapse

age

age in months

in.subcohort

Included in the subcohort for the example in the paper

Note

The usage above assumes that the survival package is attached via library(survival) or via another package that depends on survival, e.g., mstate. If not, then either survival::nwtco can be used or data(nwtco, package="survival").

References

NE Breslow and N Chatterjee (1999), Design and analysis of two-phase studies with binary outcome applied to Wilms tumour prognosis. Applied Statistics 48, 457–68.

Examples

with(nwtco, table(instit,histol))
anova(coxph(Surv(edrel,rel)~histol+instit,data=nwtco))
anova(coxph(Surv(edrel,rel)~instit+histol,data=nwtco))

survival documentation built on Sept. 10, 2026, 1:07 a.m.