04-07-2017 05:40 PM
What's the definition of an unscheduled visit?
Please post the data as a data step, see examples from your previous questions as well as what the results should look like. Anything you've tried so far would also be helpful.
PS. It seems like you post a question, then try to work on it or continue working on it. I would highly suggest trying to phrase your questions according to the 'How to Ask a Good Question' guidelines. 80% of the time I find the answer myself before I finish that process.
04-07-2017 05:43 PM
I am guessing that you want to identify the dates where doses were missed. If that is so, then one possibility would be:
data test; informat date date9.; format date date9.; input id $ date dose; cards; 001 01jan2012 10 001 08jan2012 20 001 20jan2012 30 001 27jan2012 40 001 02jan2012 99 001 03jan2012 99 002 02jan2012 10 002 05jan2012 20 002 03jan2012 99 ; data want (drop=date last_date dose rename=(missed_date=date)); set test; format missed_date date9.; by id; last_date=ifn(first.id,date,lag(date)); if date-last_date gt 1 then do; do missed_date=last_date+1 to date-1; output; end; end; run;
Art, CEO, AnalystFinder.com