how to count something using proc sql

appleorange — Thu, 02 Apr 2015 18:05:27 GMT

I have a dataset (patients) as such:

Pat_ID Hos Date

A 11 1/1/2012

B 12 2/3/2012

B 13 2/3/2012

C 11 4/1/2012

C 11 4/5/2012

How do I count using proc sql such that the outcome looks something like this:

Pat_ID Visits

A 1

B 1

C 2

Since B has two visits on the same date, they are considered as only 1 visit, whereas C has 2 visits because they are on different dates.

Re: how to count something using proc sql

billfish — Thu, 02 Apr 2015 18:20:32 GMT

you can try:

proc sql;

select pat_id, count(distinct date) as visits

from patients

group by pat_id;

quit;