NONMEM Users Network Archive

Hosted by Cognigen

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:
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"

Best regards, Andreas.

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


¿Necesita imprimir este mensaje? Protejamos el medio ambiente.
Li cal imprimir aquest missatge? Protegim el medi ambient.
Do you need to print this message? Let's protect the environment.

Este mensaje, y en su caso, cualquier fichero anexo al mismo, puede
contener información confidencial, siendo para uso exclusivo del
destinatario, quedando prohibida su divulgación, copia o distribución a=
terceros sin la autorización expresa del remitente. Si Vd. ha recibido
este mensaje erróneamente, se ruega lo notifique al remitente y proceda a=
su borrado. Gracias por su colaboración.

This message and its annexed files may contain confidential information
which is exclusively for the use of the addressee. It is strictly
forbidden to distribute copies to third parties without the explicit
permission of the sender. If you receive this message by mistake, please
notify it to the sender and make sure to delete it. Thank you for your
kind cooperation.

(image/gif attachment: 01-part)

(image/gif attachment: 02-part)

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

The NONMEM Users Network is maintained by ICON plc. Requests to subscribe to the network should be sent to:

Once subscribed, you may contribute to the discussion by emailing: