Flag Maximum Encounter Date(s)

[BTAinRVA]

Hello Everybody!

I've got a data set and I'm trying to create a variable that will flag the last Encounter_Date for each patient for each fiscal month/fiscal year. They may have multiple encounters on the last Encounter_Date. I'm trying to replicate the results of this code:

proc sql;

create table bbb as select * from aaa

group by fy, fm, ppid

 having encounter_date = max(encounter_date);

quit;

with something like this (I want to keep all records in aaa and flag the max(encounter_date)):

proc sort data = aaa;

by FY FM ppid encounter_date;

run;

data bbb;

set aaa;

by FY FM ppid;

if last.ppid then Max_Enc_Date = 1 ;

else Max_Enc_Date =0 ;

run;

Thanks,

Brian

[Astounding · Accepted solution]

To keep several observations, all with the same maximum date, sort in descending order:

proc sort data=aaa;

by fy fm ppid descending encounter_date;

run;

Then it is easy to select all those having the maximum:

data want;

set have;

by fy fm ppid;

if first.ppid then max_date = encounter_date;

retain max_date;

Max_Enc_Date = (encounter_date = max_date);

drop max_date;

run;

[BTAinRVA]

That's Astounding!

Thank you!