RE: WRES AND OUTLIER IDENTIFICATION/EXCLUSION

From: "Mats Karlsson" mats.karlsson@farmbio.uu.se Subject: RE: [NMusers] WRES AND OUTLIER IDENTIFICATION/EXCLUSION Date: Tue, 26 Sep 2006 15:53:13 +0200 Hi, I believe that sensitivity to outliers/errors, when present, may well come from the assumption that residual error magnitude is the same across all subjects. This assumption is usually proven wrong when challenged and a model that allows variability in sigma between subjects is preferable. This can easily be accomplished with FOCEI and a coding of the type Y=F+EPS(1)*EXP(ETA(.)). Best regards, Mats Mats Karlsson, PhD Professor of Pharmacometrics Div. of Pharmacokinetics and Drug Therapy Dept. of Pharmaceutical Biosciences Faculty of Pharmacy Uppsala University Box 591 SE-751 24 Uppsala Sweden phone +46 18 471 4105 fax +46 18 471 4003 mats.karlsson@farmbio.uu.se