st: Programming: Ranking hospitals according to admissions in a dataset with patient level data

[Andreas Schmid <andreas.schmid@uni-bayreuth.de>]

Dear Statalist users,

I am working with a patient dataset which contains information on each 
admitted patient as well as on the according hospitals. For further 
steps I need a rank number for each hospital according to admissions per 
year. The variable "admissions" already exists. As for each hospital 
there are a couple of thousand observations (i.e. patients), I can not 
just use egen ranking = rank(admissions), as this would try to rank each 
individual observation.
Is there any way to generate a variable ranking that gives in each 
observation the same rank for one particular hospital?
Example:
Hospital A has got 5000 admissions per year and is thus the second 
largest hospital according to admissions. Thus, for any patient admitted 
to hospital a the variable ranking shows "2".
Structure:
Hospital-ID Admissions Sex Age | RANKING
A 5000 male 15 | 2
A 5000 female 56 | 2
B 3000 male 60 | 6
A 5000 male 70 | 2
B 3000 male 71 | 6
...
...
...

Thanks a lot for your help!

Andreas

--
Andreas Schmid
University of Bayreuth
Germany
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