riskRegression (version 1.4.3)

extractStrata: Extract the information about the strata

Description

Extract the information about the strata stored in a Cox model

Usage

extractStrata(xterms, xlevels = NULL, special)

Arguments

xterms

...

xlevels

...

special

the special character indicating the strata variables

Examples

# NOT RUN {
d <- sampleData(1e2, outcome = "survival")
d$entry <- 0

##
library(survival)
mCox <- coxph(Surv(time, event) ~ X1+X2, data = d)
extractStrata(delete.response(mCox$terms), special = CoxSpecialStrata(mCox))

mCox <- coxph(Surv(event, time = entry, time2 = time) ~ strata(X1)+strata(X2), data = d)
extractStrata(delete.response(mCox$terms),
              xlevels =  mCox$xlevels, special = CoxSpecialStrata(mCox))

##
library(rms)
mCox <- cph(Surv(time, event) ~ X1+X2, data = d)
extractStrata(delete.response(mCox$terms), special = CoxSpecialStrata(mCox))

mCox <- cph(Surv(event, time = entry, time2 = time) ~ strat(X1)+strat(X2), data = d)
extractStrata(delete.response(mCox$terms),
              xlevels =  mCox$xlevels, special = CoxSpecialStrata(mCox))

# }