NONMEM Users Network Archive

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Re: Meta-analysis with Nonmem

From: alindauer-research
Date: Fri, 26 Feb 2010 10:26:10 +0100

Thank you Leonid and Dirk for your replies. They were very helpful.

Leonid, what would you think about the following:
Y=IPRED+SE*EPS(1)+ETA(1)
With SIGMA fixed to 1 and OMEGA being the inter-study standard-deviation?
What would be the interpretation of SIGMA if it were not fixed to 1?
You wrote:
>>Y=IPRED+SE*EXP(ETA(1))*EPS(1)), etc.
Wouldn't this be somehow transformed by NONMEM because of the
linearization process? Similarly to why we cannot use the exponential
residual error model directly in NONMEM, but have to do the
transform-both-sides approach.

Dirk, good idea. However, estimation of the simulated datasets might
become very time consuming when you combine data from several large
studies. And, as you said:
>> If the number of subjects in a study is small, it might be useful to
repeat the simulation and produce different combined datasets.
I would even go further and say, that it is absolutly necessary to repeat
the simulation-reestimation procedure many times in order to get "stable"
results.

Best regards, Andreas.



Andreas Lindauer
Pharmacokineticist
Pharmacokinetics and Metabolism
R&D Center. Ferrer Internacional S.A.
Juan de Sada 32, 08028 Barcelona


alindauer-research
www.ferrergrupo.com







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Received on Fri Feb 26 2010 - 04:26:10 EST

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