I am creating my dataset to carry out a survival analysis. I have these variables:
CASE_ID
, i_birthdate_c
, i_deathdate_c
, difftime_c
, event1
, enddate
.
Case_id
= unique IDbirthdate
= subject, enters observationdeathdate
= when they dieddifftime_c
is the time from birth to deathevent1
= censoring variable indicating death has or has not occurredenddate
= when all subjects will be censored if the event has not occurred.
I am trying to calculate the time from i_birthdate_c
to enddate
(12/31/2013). I want this value to be finally populated in my difftime_c
variable if the event1 = 0. As it stands, I have the time from i_birthdate_c
to i_deathdate_c
for when event1
= 1.
What would be the most efficient way of accomplishing this in R with the existing code I have below? I keep striking out with my if statements.
Model:
newdata$difftime_c <- difftime(newdata$deathdate_c,newdata$birthdate_c,units="weeks")