# NOT RUN {
library(nlme)
library(survival)
library(geepack)
library(data.table)
data(Phenobarb)
Phenobarb$event <- 1-as.numeric(is.na(Phenobarb$conc))
data <- Phenobarb
data <- data[data$event==1,]
data$id <- as.numeric(data$Subject)
data <- data[data$time<16*24,]
data <- lagfn(data, lagvars=c("time","conc"), id="Subject", time="time", lagfirst = NA)
head(data)
mph <- coxph(Surv(time.lag,time,event)~I(conc.lag>0 & conc.lag<=20) + I(conc.lag>20 & conc.lag<=30)
+ I(conc.lag>30)+ cluster(id),,data=data)
summary(mph)
data$weight <- iiw(mph,data,"id","time",TRUE)
head(data)
# }
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