Re: Model building question

From: Harry Mager harry.mager@bayerhealthcare.com Subject: Re: [NMusers] Model building question Date: 01-Mar-2005 10:22 Mark, Of course I totally agree with you, one minor remark, however. Even if the information content in 2 covariates it is nearly the same, it may well happen that both are retained in a relationship. In this case, you may end up with a very high measure for the association between DV and the model predictiions, but the regression coefficients tend to be very large (pretending a strong relationship) but with opposite signs (very strong, opposite influence of the covariates on the the dependent variable). There seems to be no way to avoid a careful examination of the covariate structure and its potential implications on regression coefficient variabilities. Harry Dr. Harry Mager Head Global Pharmacometrics Bayer Healthcare AG BHC-PH-PD-GMD-GB Biometry & Pharmacometry D-42096 Wuppertal / Bldg. 470 Telefon: +49 (0) 202-36-8891 Telefax: +49 (0) 202-36-4788 eMail: Harry.Mager.HM@Bayer-AG.de