RE: order of covariate inclusion -> avoiding stepwise a pproaches -> abandoning exploratory analysis?
From: mark.e.sale@gsk.com
Subject: RE: [NMusers] order of covariate inclusion -> avoiding stepwise a pproaches -> abandoning exploratory analysis?
Date: 9/29/2003 12:41 PM
Leonid
My last email on this, I promise. We have several examples of cases where
your convexity assumption (which I called monotonically downhill) is not the
case, formally reported by Janet Wade et al. What this means is that the answer
you get depends on how you get there, and different users will get different
answers for the same data set, with the same prior - not a good result for a
scientific analysis. This is not uncommon, in fact it is essentially invariably the case.
For my last commercial, all will become clear at Paolo Vicini's symposium at
AAPS Wed Oct 29, "What is the right model? Issues surrounding the evaluation of
Pharmacostatisical Models in Drug Development" (Well, maybe not completely clear).
Mark