data ab2 dup;
set ab1;
by id date;
if first.date then output ab2;
else output dup;
run;
A patient has multiple visits and I only need to see the first vist. But with the above code, I cannot find any duplicate records.
ANy advice how to remove the same ID with later visits, that might be second, third or even more visits?
Thanks.
If you want one per ID then use
if first.id then output ab2;
else output dup;
You haven't shown your data, but I assume from the code that each row of data has a different value in DATE variable. Therefore when:
if first.date
Is evaluated every row is different. Do you not have a visit variable, i.e. VISIT 1, VISIT 2 etc. you could use that. Or if the DATE variable is actually a datetime then use datepart() function to use only the date. Without further information on your data I can't say.
yes each row of data has a different value in date variable
I do not have a visit variable, and date variable is a datetime,
can you provide a sas sample code as how to use datepart( )?
Thanks
If you want one per ID then use
if first.id then output ab2;
else output dup;
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