Grouping people by the dates they enrolled in a study.

[pramenon1]

Hi,

I have data regarding when patients enrolled in study from 01/01/1992 to 12/31/2019. I am trying to put these patients into 4 groups like this below:

DATA dtanl.hivcancerdta_enrlgrp;
set dtanl.hivcancerdta;
format lastdate date9.;
enrolldt = DATEPART (lastdate);
IF enrolldt = . THEN enrlgrp = .;
ELSE IF '01JAN1992'D <= enrolldt < '01JAN1998'D THEN enrlgrp = 1;
ELSE IF '01JAN1998'D <= enrolldt < '01JAN2004'D THEN enrlgrp = 2;
ELSE IF '01JAN2004'D <= enrolldt < '01JAN2010'D THEN enrlgrp = 3;
ELSE IF enrolldt >= '01JAN2010'D THEN enrlgrp = 4;

RUN;

When doing this, the variable enrolldt fills as 0 and enrlgrp fills as missing.

I was having trouble with this and looked at other SAS community threads detailing similar issues but no matter what I tried it isnt working. Any help would be appreciated.

Thanks!

[PGStats · Accepted solution]

DATEPART is to convert SAS datime values to SAS date values. I suspect that lastdate is already a SAS date value. Try replacing

enrolldt = DATEPART (lastdate);

with

enrolldt = lastdate;

[pramenon1]

Thank you so much for your quick reply! This worked perfectly!