Re: Model building question

From: jeffrey.a.wald@gsk.com Subject: Re: [NMusers] Model building question Date: Tue, March 1, 2005 10:29 am From a formalistic perspective I'd have to agree with Mark. From a pragmatic perspective I would agree with a reworded version of Nick's statement. "The sequence of model building should not affect substantial inferences" However, this thread raises a question in my mind. Is the coda of Nick's statement "but sometimes it does" really true when we limit ourselves to consideration of substantial inferences (i.e., drug label changes, dose adjustments, etc...)? I would be curious to learn of real-life examples in which different model building sequences have led to "equivalent" models with substantially different clinical manifestations. I think the field of combinatorial optimization offers the possibility for increased automation of model building which in and of itself might yield great benefits. However, in my somewhat intentionally provocative opinion (IMSIPO) I am not convinced that when we do what we do already (with adequate expertise) that we are somehow failing to identify clinically meaningful (actionable) conclusions. Jeff Jeff Wald, PhD jeffrey.a.wald@gsk.com Clinical Pharmacokinetics/Modeling and Simulation Neurology and GI RTP, NC