NONMEM Users Network Archive

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RE: Two compartment model with fixed omega parameters

From: Martin Bergstrand <martin.bergstrand>
Date: Tue, 27 Jun 2017 11:29:42 +0200

Dear Waroonrat,

To know if a model “adequately describe the data” you need =
to study model
diagnostics. Read more for example here:

The AIC numbers in your case indicate that the two compartment model is a
much better description of your data than the one compartment model (read
on AIC here:
However, this is only a relative comparison and as pointed out before does
not say anything about whether any of the models “adequately descri=
be the

All the best,

Martin Bergstrand, Ph.D.

Senior Consultant

Pharmetheus AB

*From:* owner-nmusers
Behalf Of *Waroonrat Sukarnjanaset
*Sent:* Tuesday, June 27, 2017 10:52 AM
*To:* nmusers
*Subject:* [NMusers] Two compartment model with fixed omega parameters

Dear NMusers,

I have tried to find an appropriate base model.

I found that two compartment model with fixed Omega of V2 and Omega of Q =
0 (AIC 1860.17) provided smaller AIC than one compartment model (AIC
1921.83) did.

From these findings (no variability on V2 and Q), is it suggesting that one
cpt model could adequately describe the data?

I would truly appreciate it if you could give me some suggestions.

Kind regards,


Received on Tue Jun 27 2017 - 05:29:42 EDT

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