weighting

From: Chantal Csajka <Chantal.Csajka@chuv.hospvd.ch> Subject: weighting Date: Mon, 20 Aug 2001 16:38:54 +0200 Dear nonmem users, I am currently modeling concentration data from routine patient care in a TDM framework. Several patients showed concentrations deviating clearly from the expectation and were therefore repeatedly sampled. I think this results in biased parameter estimates, as the few deviant individuals provided a lot of data points. Is there a way to weight the data, say by the inverse of the number of observations per patient, so that NONMEM takes into account the oversampling and limits the bias ? Thank you Chantal Csajka, PhD Division of Clinical Pharmacology Beaumont 6 CHUV 1011 Lausanne, Switzerland tel: 021/ 314.42.57 fax: 021/ 314.42.66 email: chantal.csajka@chuv.hospvd.ch