Re: Model building question

From: "Nick Holford" n.holford@auckland.ac.nz Subject: Re: [NMusers] Model building question Date: Mon, February 28, 2005 4:23 pm Kai, IMHO there are no 'correct' answers to your questions. The sequence of model building should not affect the results but sometimes it does. This is in part due to lack of adequate information in the design and in part due to NONMEM's limitations. I would prefer to estimate BOV as part of the base model first. I would then test for a systematic change in parameters that you have some a priori reason to think may have changed from occasion to occasion. The best test criterion is something based on the predictive performance of the model rather than rejection of the null hypothesis using some approximation to the distribution of delta OBJ. Nick -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x86730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/