Hi, I am using SAS 9.4 and am having trouble getting the data organized how I would like.
Here is an example of data I have:
ID Testdate TestResultPositive
1 -10 1
1 0 1
1 19 1
2 -30 1
2 0 0
2 15 1
2 45 1
I don't care about how many of the testdays had the same test results, but I am interested in whether test results went from positive to negative and back to positive again over time. So here is how I would like my data to look:
ID Day TestResultPositive
1 -10 1
2 -30 1
2 0 0
2 15 1
When i sort by id and testresultpositve with the nodupkey option, I wind up getting this (which loses the information about ID 2 having another positive test result on day 15):
proc sort data=have nodupkey; by id testresultpositive; run;
ID Day TestResultPositive
1 -10 1
2 -30 1
2 0 0
Any other ideas? Thanks so much in advance!
what is your expected result for your input sample?
Should i assume you are looking to for something like this?
data have;
input ID Testdate TestResultPositive;
cards;
1 -10 1
1 0 1
1 19 1
2 -30 1
2 0 0
2 15 1
2 45 1
;
data want;
set have;
by id TestResultPositive notsorted;
if first.TestResultPositive;
run;
Have you attempted looping a lag function over the id?
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