topic Re: Assignments of visit number based on date in SAS Programming

Assignments of visit number based on date

abc44 — Fri, 14 Sep 2018 22:07:17 GMT

Hi all,

I have a relatively simple task I need some help with.

I would like to assign a visit # to assessments that were performed on different dates for the same subject ID. Does someone know how I can generate this 3rd column called visit?

ID Date Visit

1 01/02/2018 1

1 08/08/2018 2

2 04/03/2018 1

2 09/09/2018 2

etc.

I basically need to assign a visit number per date within each subject ID, but am struggling with the code.

I look forward to your feedback!
Thanks in advance!

Re: Assignments of visit number based on date

novinosrin — Fri, 14 Sep 2018 22:12:27 GMT

data want;
set have;
by id date ;
if first.id then visit=1;
else if first.date then visit+1;
run;

Re: Assignments of visit number based on date

abc44 — Fri, 14 Sep 2018 22:29:14 GMT

This works- thanks so much!

Re: Assignments of visit number based on date

novinosrin — Fri, 14 Sep 2018 22:33:02 GMT

a teaser fun i learned from genius PD's dazzle playing with PDV . Don't use this, but play with it. It's a joy as it gives an intuition of how DOW works 🙂

data want1;
if 0 then set have;
visit=0;
do until(last.id);
visit+1;
do until(last.date);
set have;
by id date;
output;
end;
end;
run;