BookmarkSubscribeRSS Feed
Carl190
Calcite | Level 5
Hi all.

My data is a 3-level data (level 1: repeated measures, level 2: patients, level 3: clinics).

I wonder if PROC NLMIXED can be used for 3-level data.

I am getting conflicting answers to this.

Thanks in advance for your help.

Carl
2 REPLIES 2
lvm
Rhodochrosite | Level 12 lvm
Rhodochrosite | Level 12
Because there is only one allowed RANDOM statement with one SUBJECT option, many people think that NLMIXED is only for 2-level hierarchies. But if you understand variance-covariance matrices, one can force NLMIXED to fit multiple-hierarchy models to data. This is tricky, requiring a lot of coding. It is not the type of thing that can be simply written out here (at least for me). Example 15.4 in Littell et al. (2006; SAS for Mixed Modell, 2nd edition) deals with this explicitly. You can buy this for SAS Press or Amazon (etc.).
Carl190
Calcite | Level 5
I got this book, I will check the example.

Thanks for your suggestion,
Carl.

sas-innovate-2024.png

Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.

Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.

 

Register now!

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 2 replies
  • 1337 views
  • 0 likes
  • 2 in conversation