M. Khedr wrote:
> I have a data set similar to Stanford heart transplant
> data
>
> 1. some patients on waiting list who did not receive a
> transplanted organ
>
> 2. others received a transplanted organ
>
> if we want to consider transplantation as a time
> dependent covariate " the risk of death before
> transplantation is deferent form the risk after
> transplantation". knowing that we have
>
> Listing date
> Transplantation date
> Last seen date
>
> and one record per patient
>
> how to generate a time dependent covariate in this
> case.
Use -stsplit- to split the records at transplantation date
(after you have properly -stset- your data):
. stsplit transplant, after(transplantdate) at(0)
(assuming that 'transplantdate' is in the same units as the timevar in
-stset- and transplantdate==. for cases without transplantation)
The new variable 'transplant' will equal -1 before transplantation and 0
thereafter. So you might want to recode:
. replace transplant=transplant+1
I hope this works.
ben
PS: Also see -stsplit- in the ST-manual (Example 3 on p. 337). The
approach presented there is, however, much more complicated.
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