RE: GAM analysis and further action

From: "Mats Karlsson" mats.karlsson@farmbio.uu.se Subject: RE: [NMusers] GAM analysis and further action Date: Wed, 29 Mar 2006 20:35:42 +0200 Hi Toufigh, You have both BW and HT as candidate covariates. These are often highly correlated. Unless you have a very large data set, it is unlikely that you can separate the influence from the two. Allowing highly correlated covariates often results in models that have highly influential individuals. You can look at Cook score diagnostics in Xpose and also delete individuals (also doable in Xpose) to investigate sensitivity. However, I would not use GAM results as the final and they are really quite uninteresting to relate to p-values. It is a guide for what to try (and sometimes with what functional form) in NONMEM. 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