Re: NONMEM Unexpected result with the $LEVEL statement

On 8/13/2019 4:39 PM, Dumortier, Thomas wrote: > Hello > > I would like to model inter-study variability on the of the inter-subject variability with NONMEM 74 > > A subject belongs to a study, therefore those two random effects are nested > > Following the instruction, I code as below, where ETA8 is at the subject level and ETA9 is at the study (STUD) level. > > $INPUT ID STUD TIME TIM2 TAD NT CMT EVID MDV BLOQ AMT DOSE RATE LIDV=DV LNDV WT0 TRT1S TRT2S PAS0 > > ... > > $PK > > ... > > TVF1 = THETA(8) + ETA(8) + ETA(9) > > F1 = (EXP(TVF1)/(1+EXP(TVF1))) > > ... > > $LEVEL STUD=(9[8]) > > The fit with NONMEM 743 (fortran compliler) seems correct and the estimates for the variance (OMEGA) of ETA8 and for ETA9 are provided. > > But when looking at the ETA9 values (the empirical bayes estimates), I notice that > > (1)Different subjects of the same study have different ETA9 values, while I would expect that all subjects of a study have same ETA9 value > > (2)The ETA9 value is proportional to the ETA8 value (ie, plotting ETA8 versus ETA9 from all subjects of all studiers results in all points on the same diagonal line) > > Am I coding incorrectly ? > > Any help would be more than welcome > > Many thanks > > Thomas Dumortier > > *Thomas Dumortier* > > Director Pharmacometrics > > Novartis Pharma AG > > Postfach > > CH-4002 Basel > > SWITZERLAND > > Phone +41 61 3240946 > > Fax +41 61 3241246 > > [email protected] <mailto:[email protected]>__