high correlation between variance terms and shared approach

Phoenix Certara Forums Modelling and Simulation
1

Hi, I have a question on addressing the high correlation between variance terms with (r-value is above 0.9). Trying an alternative parametrization approach could fix this issue (shared. approach).
I am attaching a part from the published article by Mould DR, Upton RN explaining this approach, but I do not know how to do it using NLME.
Can I get help on how to write PML for the shared approach?
Thanks

High R.jpg
High R.jpg717×461 92.3 KB

2

Hi David,

I have send you a ilink (youtube) which could be of use to you in converting the published data to a model

https://www.youtube.com/watch?v=0Hr4UnT07BQ

Rebuilding a Population PK Model From a Literature Reference Presented by Bernd Wendt

I hope this could be of use t o you.

Rebuilding a Population PK Model From a Literature Reference Presented by Bernd Wendt

3

The attached Phoenix project has 2 models, “FullBlock” with an individual eta term on each parameter, and “Shared”, which shows how you can code the shared model.

Hope this helps!

Theo_shared_approach.phxproj (1.62 MB)

4

Thanks, Cradhakr for sharing the link.

5

Thanks, Kniefort for your help, Can you please reattached the project, I think it was not attached with your post.

Best

6

You are correct. Apologies. Post above edited with attachment.

7

Thank you so much for updating the post with the file!!