RE: Covariate Models Using Weight

From: "Piotrovskij, Vladimir [JanBe]" <VPIOTROV@janbe.jnj.com> Subject: RE: Covariate Models Using Weight Date: Fri, 19 Nov 1999 12:09:44 +0100 Good point, Steve. Mechanistic considerations are very useful and can guide model development. Just one example from own practice: a drug is eliminated exclusively via renal route. WT and CLCR are almost equal as predictors for CL. What to prefer? I prefer CLCR to WT since I know the mechanism of elimination. CLCR and WT are highly correlated and that is why the inclusion of WT in CL submodel works as well as CLCR. The problem of correleted predictors! Mechanistic considerations help selecting right predictors. Vladimir ---------------------------------------------------------------------- Vladimir Piotrovsky, Ph.D. Janssen Research Foundation Clinical Pharmacokinetics B-2340 Beerse Belgium Email: vpiotrov@janbe.jnj.com