search for: fitagefollowup

Displaying 1 result from an estimated 1 matches for "fitagefollowup".

2007 Feb 05
2
Two ways to deal with age in Cox model
...1,0), age= c(0, 2,1,1,1,0,0), riskfactor= c(0, 0,0,0,1,1,1)) fitagecovariate<-coxph( Surv(time, status) ~ age +riskfactor, test1) fitagecovariate Age included as part of follow-up time: test2<-test1 test2$timeplusage<-test2$time+test2$age fitagefollowup<-coxph( Surv(timeplusage, status) ~ riskfactor, test2) fitagefollowup I would appreciate any thoughts about the differences in the interpretation of the two models. One obvious difference is that in the first model (fitagecovariate) one can make inferences about age and in the second one canno...