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: 1. Jadhav, P. R. & Gobburu, J. V. S. A new equivalence based metric for predictive check to qualify mixed-effects models. *AAPS J* *7,* E523–E531 (2005). 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 <[email protected]> wrote: > Dear all: > > I'm now having a set of TDM data, only troughs （C0 ） available. > 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 a > 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 purpose > or not." > > > > Thank you in advance. > > > > Yours, > > Chenyan Zhao > > Email: *zhaochenyanvictory@**hotmail.com <http://hotmail.com>* > > Mobile: +86 13917430219 > > >
