Dear Statalisters,
I have a dataset as shown with a unique id no (urno) and a date of an
episode of interest. As can be seen there can be 'multiple episodes' for
each unique id but also multiple episodes on the same date for each
unique id. I want to create an identifier (new variable below) that
labels each date as a separate episode for each patient (ie 1,2,3�) but
not for the same date. For two episodes on the same date I would like
the same number to be allocated (see below id 10069 & 166056):
Data set sorted for id and date
+---------------------+
urno date new variable
---------------------
1. 29665 09 Mar 93 1
2. 29665 19 May 93 2
3. 29665 09 Aug 93 3
4. 29665 05 Mar 94 4
5. 29665 20 Apr 94 5
---------------------
6. 29665 27 Jul 94 6
7. 29665 07 Jan 95 7
8. 78602 09 Jun 92 1
9. 78602 07 Jul 92 2
10. 100069 11 Mar 99 1
---------------------
11. 100069 06 Apr 99 2
12. 100069 06 Apr 99 2
13. 131608 15 Oct 02 1
14. 145132 30 Aug 01 1
15. 145132 20 May 02 2
---------------------
16. 166056 16 Jun 92 1
17. 166056 26 Jul 94 2
18. 166056 27 Mar 95 3
19. 166056 09 Mar 98 4
20. 166056 09 Mar 98 4
---------------------
I hope this all makes sense. Does anyone know a way of doing this? Tried
explicit subscripting but can seem to do exactly what I want. Unable to
find any clue for archives or stata FAQ.
Thanks very much
kevan
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