topic Re: Delete all duplicates by condition of first observation in SAS Programming

Delete all duplicates by condition of first observation

htht — Thu, 17 Sep 2020 09:35:14 GMT

Hi all,

I had this situation where I need to exclude all the ID's with history is 1 on the first observation. For example, in the below scenario there are multiple observations for each ID. I want to delete all those ID's which had history of disease (=1) on the first observation.

Data I have

ID	Order of occurrence	History
1	1	1
1	2	1
1	3	1
2	1	1
3	1	0
3	2	1
4	1	0
5	1	0
5	2	1

Data i want to keep

ID	Order of occurrence	History
3	1	0
3	2	1
4	1	0
5	1	0
5	2	1

I tried so many time but i can't get the result I want. Please help me. Thanks in advance for the support.

Re: Delete all duplicates by condition of first observation

yabwon — Thu, 17 Sep 2020 09:50:32 GMT

Assuming your data are already sorted properly, try this:

data have;
input ID	Order_of_occurrence	History;
cards;
1	1	1
1	2	1
1	3	1
2	1	1
3	1	0
3	2	1
4	1	0
5	1	0
5	2	1
;
run;

data want;
  do until(last.ID);
    set have;
    by ID;

    if first.ID = history then _N_ = 0;
    if _N_ then output;
  end;
run;

Bart

Re: Delete all duplicates by condition of first observation

htht — Thu, 17 Sep 2020 10:10:48 GMT

Thank you Bart for your support.