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RE: VPC appropriateness in complex PK

From: Martin Bergstrand <martin.bergstrand>
Date: Mon, 21 Sep 2009 19:22:09 +0200

Dear Marco,


It is correct that PC-VPCs is currently not a feature in PsN. The =
standard VPC command in PsN can still be used for most of the =
calculations needed to produce a PC-VPC, however calculation of median =
PRED in each bin must currently be calculated outside of PsN. This =
calculation is needed once for a data-set and a specific choice of =
binning. The calculated median PRED is appended together with PRED in =
the data-file.


In the model file used to construct the VPC the following code is added:



    PCDV = Y * MPR/PR


    PCDV = DV * MPR/PR



;; PR = Typical model prediction (PRED) for the current observation =
(appended in the input data)

;; MPR = Median PRED in the current bin (appended in the input data)


When the VPC command in PsN is executed you add =
”-dv=PCDV” at the command line. It is important that =
you chose binning options in PsN so that it corresponds to the binning =
you have done when calculating median PRED (MPR).


PRED correction will from my understanding eventually be an option in =
the PsN VPC functionality. Currently however all programming efforts for =
PsN are focused on making the existing functionalities compatible with =
NONMEM 7. Therefore I am not sure if PRED correction is going to be =
included already in the next release.


Best regards,



From: marco.campioni
Sent: den 21 september 2009 17:44
To: Martin Bergstrand
Cc: 'Dider Heine'; nmusers
Subject: RE: [NMusers] VPC appropriateness in complex PK


Dear Martin and Uppsala group,

Maybe I’m wrong, but I guess PC-VPC is not available in the =
current version of PsN.

Did you plan to implement it in the new PsN version?

Many thanks

Kind Regards


Marco Campioni, PhD
Modelling & Simulations
Exploratory Medicine

Merck Serono S.A. - Geneva
9, Chemin des Mines
1202 Geneva, Switzerland
Location: B1.4
Phone: +41 22 414 4554
Fax: +41 22 414 3059
Email: marco.campioni

Received on Mon Sep 21 2009 - 13:22:09 EDT

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