How to select the last observation from a dataset to perform a match-merge?

[steeleye]

Hello!

I am currently working on performing a match-merge across four data sets. Each observation should include a unique SSN; however one dataset records four observations per one SSN. How would I go about including only the last recorded observation for each unique SSN to my final match-merged dataset?

The observations for the data set in question would be structured similarly to:

111-11-1111 ...

111-11-1111 ...

111-11-1111 ...

111-11-1111 ...

222-22-2222 ...

222-22-2222 ...

222-22-2222 ...

222-22-2222 ...

...

[SASKiwi]

Do you have a recorded date in your data to sort on as well as SSN? If not how would you identify the last recorded SSN?

[steeleye]

Yes, there is a corresponding visit date for each observation. We are being asked to select the observation with the most recent visit date per SSN.

[SASKiwi · Accepted solution]

proc sort data = Have;
  by SSN Visit_Date;
run;

data Want;
  set Have;
  by SSN;
  if last.SSN;
run;

[steeleye]

Thank you so much, this worked perfectly!

[PeterClemmensen]

Can you show us your code so far?

[steeleye]

No I'm sorry, this code is for a class so I cannot provide my code verbatim.