finding frequency of a specific drug one per id

[lillymaginta]

id  drug     v_date 
1   11         01/02/2004
1    11        03/03/2005
1    11        8/3/2005        
1    22        5/4/2005
1   22         6/6/2005

Hi All,

I have something similar with the above database. Multiple drugs per id and the same drug can have more than one v_date. My question I want to find the number of patients who obtained at least one drug (for example at least 1 of drug number 11) . So if I have 10 patient who had at least one of drug (no 11) in different v_date, I want to obtain an output that state: drug 11 frequency= 10, and so on 

[FreelanceReinh · Accepted solution]

Hi @lillymaginta,

Try this:

proc sql;
create table want as
select drug, count(distinct id) as frequency
from have
group by drug;
quit;

[lillymaginta]

Thank you FreelanceReinhard