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Re: pcVPC or NPDE

From: Devin Pastoor <devin.pastoor>
Date: Fri, 11 Sep 2015 14:45:52 +0000

Dear Chenyan,

Appropriateness is largely a matter of what the ultimate purpose of the
model is, and neither metric will be 'better' in all cases. Extrapolating
into a new population may require different evaluation diagnostics than
using a model to optimize the dose the observed population.

Given you only have trough samples, using a posterior predictive check on
trough levels or equivalence criteria such as proposed in:

Jadhav, P. R. & Gobburu, J. V. S. A new equivalence based metric for
predictive check to qualify mixed-effects models. *AAPS J* *7,* E523=

would likely work well.

Devin Pastoor
Clinical Research Scientist, PhD student
Center for Translational Medicine
University of Maryland, School of Pharmacy

On Fri, Sep 11, 2015 at 10:38 AM ZhaoChenyan <zhaochenyanvictory

> Dear all:
> I'm now having a set of TDM data, only troughs (C0 ) avai=
> I intend to evaluated the appropriateness of the constructed model.
> My question is whether to use pcVPC or NPDE as a diagnostic tool in such =
> case?
> Which one is better?
> Or to use them both, as suggested by Bergstrand et al.: "The best
> practice most likely lies in using a wide toolbox of diagnostics, rather
> than one single universal test to decide whether a model is fit for purpo=
> or not."
> Thank you in advance.
> Yours,
> Chenyan Zhao
> Email: *zhaochenyanvictory
> Mobile: +86 13917430219

Received on Fri Sep 11 2015 - 10:45:52 EDT

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