NONMEM Users Network Archive

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Statistical power of covariate inclusion in popPK models

From: Hammami, Ibtihel -FR <Ibtihel.Hammami>
Date: Wed, 24 Mar 2021 09:46:46 +0000

Hi,


Thank you all for your answers. I have two follow-up questions:



1. Is it mandatory to use the matrix R as a variance co-variance matr=
ix to obtain the FIM? In case we have already used other type of variance c=
o-variance matrix, should we rerun the model with matrix R setting?



2. How critical is the estimation method for the computed SE? In othe=
r words, is it relevant to compare two powers computed based on two standar=
d errors givens by different estimation algorithms?

 For example, if we used FOCE-INTER to minimize our model, could we compare=
 the power (based on the Wald test) to results given by PFIM which is based=
 on FO ?



Just for a little bit of background to clarify why we are interested in the=
 Wald test.

We are working on the comparison of different methods to compute the statis=
tical power of covariate inclusion in popPK models (SSE (gold standard), MC=
MP, PPE , and Wald test). We have also included the Wald test in our compar=
ison because it is the fastest method and mostly because it used by optimal=
 designs software. Therefore, the evaluation of the accuracy of the power d=
erived by this method could facilitate the bridging step between model vali=
dation and the design of upcoming clinical trials using optimal design soft=
ware.

Thank you in advance.

Cordially.

Ibtihel HAMMAMI.

Received on Wed Mar 24 2021 - 05:46:46 EDT

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