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OFV higher with FOCEI than FO

From: ayyappa.5.chaturvedula
Date: Wed, 10 Dec 2008 11:08:56 -0500

Thank you all for the responses and it is very useful.

Regards,
Ayyappa Chaturvedula
GlaxoSmithKline
1500 Littleton Road,
Parsippany, NJ 07054
Ph:9738892200

__________________


Dear All,

I am analyzing a data set pooled from 4 clinical studies with rich
sampling. When I fit a 2 comp oral absorption model with lag time using
FO, I got successful minimization with COV step, but minimization was not
successful when I used FO parameter estimates as initial estimates for
FOCE run. When I used FOCE with INTER minimization was successful with
COV step but the OFV is much higher (~25000 vs 20000) with FOCEI
estimation than FO. The parameter estimates make more sense with FOCEI
than FO. My questions are,

Can we get something like this or I am missing something here?
Can we compare OFV between different estimation methods (my understanding
is no and OFV in case of FO does not make a lot of sense)?


Regards,
Ayyappa Chaturvedula
GlaxoSmithKline
1500 Littleton Road,
Parsippany, NJ 07054
Ph:9738892200


Received on Wed Dec 10 2008 - 11:08:56 EST

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