This has been discussed ad infinitum. Try the archives: http://www.cognigencorp.com/nonmem/nm/
________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hong-Guang Xie Sent: Friday, July 11, 2008 12:36 PM To: [email protected] Subject: [NMusers] Your suggestions/thoughts needed on allometric base or final model Dear NMusers: As you know, body weight is an important covariate that is integrated into the final or covariate model in some cases. When analyzing pediatric pop PK data, body weight-based allometric ¾ power model is used frequently. By definition, base model is a model without any covariates. But, in the literature on the population PK in pediatrics, I noted that body weight is added to the structural model (following the principles of allometry) before starting the covariate model building in some but not in all studies. That means that some models are called allometric base models and others are not. What are their differences? For the allometric base model, body weight has been added into the base model regardless of whether it is an important covariate (in some cases, body weight is not). If body weight is not an important covariate as determined by further covariate model building, is there still the need to add body weight into the final allometric model (if its corresponding base model is one without a body weight-associated allometric component)? Logically, such a need seems to be not reasonable. How to deal with this conflict? Is there an almost agreeable thought on this issue in our community? Thank you, Hong-Guang ICON plc made the following annotations. ------------------------------------------------------------------------------ This e-mail transmission may contain confidential or legally privileged information that is intended only for the individual or entity named in the e-mail address. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or reliance upon the contents of this e-mail is strictly prohibited. If you have received this e-mail transmission in error, please reply to the sender, so that ICON plc can arrange for proper delivery, and then please delete the message. Thank You, ICON plc South County Business Park Leopardstown Dublin 18 Ireland Registered number: 145835
