RE: WRES AND OUTLIER IDENTIFICATION/EXCLUSION

From: "Andrew Hooker" andrew.hooker@farmbio.uu.se Subject: RE: [NMusers] WRES AND OUTLIER IDENTIFICATION/EXCLUSION Date: Tue, 26 Sep 2006 10:53:17 +0200 Hi Jo, If you are using the FOCE method then I dont think that using the weighted residuals as a criterion to exclude outliers is justified. The WRES are based on the FO approximation and can be severely biased even when the data is simulated from the same model you estimate from. Using some other form of metric to identify outliers (such as DV/PRED as suggested by Mark) seems preferable in this case. -Andy Andrew Hooker, Ph.D. Assistant Professor of Pharmacometrics Div. of Pharmacokinetics and Drug Therapy Dept. of Pharmaceutical Biosciences Uppsala University Box 591 751 24 Uppsala Sweden Tel: +46 18 471 4355 www.farmbio.uu.se/research.php?avd=5