BookmarkSubscribeRSS Feed
mantubiradar19
Quartz | Level 8

I have a longituidnal data (Called as SBP & DBP which are contineous variables)- which is collected on different dates and the date variable looks like 10SEP2010. I have sample ID for each patient.

 

I would like to classify first measurement of SBP, DBP of each observation into one dataset and last measurement of SBP, DBP of each observation into another dataset. 

 

How can I do this?

5 REPLIES 5
zzone
Calcite | Level 5

Browse source dataset by patient_ID and sampling_date. Output first record of a group to one dataset and the last to another. something like code below. 

 

data destination_dataset1 destination_dataset2;

  set source_dataset;

  by patient_id sampling_date;

  if first.patient_id then output destination_dataset1;

  if last.patient_id  then output destination_dataset2;

run;

mantubiradar19
Quartz | Level 8
Thank you very much Zzone! Let me try this!
mantubiradar19
Quartz | Level 8

I'm trying to computete the difference between first and last observations. Can someone tell me why I have the following note? 

 

Thanks


Capture.JPG
zzone
Calcite | Level 5

"first" / "last" refer to a subgroup which means ordering. Your code does not browse the data set in an ordered manner (you should have a "by ... " clause in it.

I'd suggest you should read a little bit the basics to understand the mechanisms behind:

http://support.sas.com/documentation/cdl/en/basess/58133/HTML/default/viewer.htm#a001302699.htm

 

mantubiradar19
Quartz | Level 8
Thanks for the reference!

hackathon24-white-horiz.png

The 2025 SAS Hackathon Kicks Off on June 11!

Watch the live Hackathon Kickoff to get all the essential information about the SAS Hackathon—including how to join, how to participate, and expert tips for success.

YouTube LinkedIn

What is Bayesian Analysis?

Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.

Find more tutorials on the SAS Users YouTube channel.

SAS Training: Just a Click Away

 Ready to level-up your skills? Choose your own adventure.

Browse our catalog!

Discussion stats
  • 5 replies
  • 2628 views
  • 0 likes
  • 2 in conversation