| survSplit {survival} | R Documentation |
Given a survival data set and a set of specified cut times, split each record into multiple subrecords at each cut time. The new data set will be in `counting process' format, with a start time, stop time, and event status for each record.
survSplit(data, cut, end, event, start, id = NULL, zero = 0, episode=NULL)
data |
data frame |
cut |
vector of timepoints to cut at |
end |
character string with name of event time variable |
event |
character string with name of censoring indicator |
start |
character string with name of start time variable (will be created if it does not exist) |
id |
character string with name of new id variable to create (optional) |
zero |
If start doesn't already exist, this is the time
that the original records start. May be a vector or single value. |
episode |
character string with name of new episode variable (optional) |
The function also works when the original data are in
counting-process format, but the id and episode options
are of little use in this context.
New, longer, data frame.
aml3<-survSplit(aml,cut=c(5,10,50),end="time",start="start",
event="status",episode="i")
summary(aml)
summary(aml3)
coxph(Surv(time,status)~x,data=aml)
## the same
coxph(Surv(start,time,status)~x,data=aml3)
aml4<-survSplit(aml3,cut=20,end="time",start="start", event="status")
coxph(Surv(start,time,status)~x,data=aml4)