Resent with fewer trailing messages. Sorry for the spam if both reached NMusers
Hi Marco, I suspect what is happening in PsN is that IWRES has not been defined in your model. If you ask for shrinkage then PsN will compute ETA shrinkage (removing the ETA=0 values) as well as “EPS” shrinkage, which is computed using IWRES. The IWRES is computed as: IWRES = (DV – IPRED)/Residual_variance Where the Residual_variance is the total expected residual variance of each data point. For an additive+ proportional error model on the normal scale the IWRES would be defined as: IPRED = F W = SQRT((IPRED*THETA(prop))**2+THETA(add)**2) ; log transformed data ; IPRD = F ;DEL = 0.0001 ;IF(IPRD.LE.DEL) IPRD=DEL ;IPRED = LOG(IPRD) ;W = SQRT(THETA(prop)**2+THETA(add)**2/IPRD**2) IRES = DV - IPRED IF(W.EQ.0) W = 1 IWRES = IRES/W Y = IPRED + W*EPS(1) $SIGMA 1 FIX Of course, if you are just interested in calculating the shrinkage of an ETA without the zero values then you can print ETA values out in a table file and compute via: Shrinkage_eta = 1 – sd(ETA)/Omega Removing the ETA=0 before computation of the sd(ETA). Best regards Andy Andrew Hooker, Ph.D. Associate Professor of Pharmacometrics Dept. of Pharmaceutical Biosciences Uppsala University Box 591, 751 24, Uppsala, Sweden Phone: +46 18 471 4355 www.farmbio.uu.se/research.php?avd=5 From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: December 07, 2010 11:16 To: Gastonguay, Marc Cc: Eleveld, DJ; Ribbing, Jakob; [email protected]; [email protected]; Pyry Välitalo Subject: Re: [NMusers] Calculating shrinkage when some etas are zero Hi to all, Do you know if there is a quick method to exclude subjects with ETA=0 from the calculation of ETA shrinkage using NONMEM 7? I also tried to use the option –shrinkage of PsN, but I get the following error: AN ERROR WAS FOUND IN THE CONTROL STATEMENTS. 187 $TABLE RECORD REQUESTS AN UNKNOWN ITEM. at /usr/lib/perl5/site_perl/5.8.8/PsN_3_2_4/nonmem.pm line 40 Kind Regards Marco ------------------------------------------------------------------------------ Marco Campioni, PhD Modelling & Simulation Senior Scientist Exploratory Medicine Merck Serono S.A. - Geneva
