Survival analysis using R

Question

On running a survival model using the survival package I encountered a strange error message which I am unable to understand.

The error message was

Error in Surv(time, event) : Time and status are different lengths

The number of observations in each column used in model1 is exactly the same.

> mydata3<-read.csv(file.choose())
> attach(mydata3)
> event<-Event
> time<-time
> x<-cbind(WDCL,Age,SEX)
> ch<-coxph(Surv(time,event)~x,method="breslow")

Thanks and Regards.

Answer 1

You need to specify the formula correctly, by adding all arguments.

Try this:

coxph(Surv(time, Event) ~ WDCL + Age + SEX, method="breslow", data = mydata3)