Calculation of WRES...

From: Jean-Marie MARTINEZ <Jean-Marie.Martinez@sanofi-synthelabo.com> Subject: [NMusers] Calculation of WRES... Date: 8/12/2003 10:34 AM Hello NM Users, I'm trying to understand how NonMem computes WRES, and I'm in trouble with this topic... Indeed, one can read in several documentations that "WRES are the RES expressed in (i.e. as fractions of) population standard deviation units", or that "The WRES is a simple normalization of the RES, viz. the RES divided by the population standard deviation of the observation." (NonMem topic 6). The problem is that I cannot recalculate WRES 'by hand', due to the fact that the expression of PopSD remains unclear to me: while IWRES is easily obtained by dividing IRES by W, the same applied to RES does not give WRES ! Thank you for your help. Regards, Jean-Marie MARTINEZ Clinical Pharmacokineticist Department of Clinical Metabolism and Pharmacokinetics SANOFI-SYNTHELABO RECHERCHE 371 rue du Professeur Joseph Blayac 34184 MONTPELLIER Cedex 04 - FRANCE