Data from the National Wilm's Tumor Study

Description

Missing data/masurement 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

Source

http://faculty.washington.edu/norm/software.html

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))