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From: Higashimori, Mitsuo <Mitsuo.Higashimori>
Date: Thu, 13 Nov 2008 12:06:16 +0900

Dear all,

I have a following error(?) massage on a poplation analysis using NONMEM =
VI.

0MINIMIZATION SUCCESSFUL
 HOWEVER, PROBLEMS OCCURRED WITH THE MINIMIZATION.
 REGARD THE RESULTS OF THE ESTIMATION STEP CAREFULLY, AND ACCEPT THEM =
ONLY
 AFTER CHECKING THAT THE COVARIANCE STEP PRODUCES REASONABLE OUTPUT.

I found it when I described a control stream to assess sex difference on =
oral clearance as shown in below,

TVCL = THETA(1) * THETA(2) ** SEX
     where SEX=0 for male and SEX=1 for female.

This message was displayed without any error message. It was not =
dissapeared even though I changed the initial parameters. However, it =
was solved when I changed the model definition. For example,

TVCL = THETA(1)
IF (SEX.EQ.1) TVCL = THETA(2)

Could you please let me know some details regarding the message. =
Especially, I'd like to know

1. What impact does this error message give the analysis result?
2. Why does it depend on the model definition?

Thanks,

_/ _/ _/ Mitsuo Higashimori, Ph.D.
_/ _/ _/ Pharmacokinetic Group, Early Phase Development Department
_/ _/ _/ Clinical Division, Research & Development
_/ _/ _/ AstraZeneca K.K.
_/ _/ _/ E-mail: Mitsuo.Higashimori


 
Received on Wed Nov 12 2008 - 22:06:16 EST

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