Re: [NMusers] SIMULATION QUESTIONS

Hi Leonid,

The Erlang distribution is specified in the model. Here is more of the
control file:
$MODEL COMP=(DEPOT,DEFDOSE) ;
       COMP=(DELA1)
       COMP=(DELA2)
       COMP=(DELA3)
       COMP=(DELA4)
       COMP=(DELA5)
       COMP=(DELA6)
       COMP=(CENTRAL,DEFOBS)
       COMP=(PERIPH)

$PK
   K12=THETA(1)*EXP(ETA(1)) ;lagtime
   K23=K12
   K34=K12
   K45=K12
   K56=K12
   K67=K12
   K78=K12

   CL=THETA(2)*EXP(ETA(2)) ; clearance 1
   V8=THETA(3)*EXP(ETA(3)) ; volum 1
   V9=THETA(4)*EXP(ETA(4)) ; volum 2
   Q=THETA(5)*EXP(ETA(5)) ; clearance 2

   K80=CL/V8
   K89=Q/V8
   K98=Q/V9
   S8=V8

The reason for using ADVAN 5 is because of the Erlang distribution, which
was found to best describe the lagged absorption. And since the optimum
number of lag-compartment was found to be 6, this gives CMT 8 (the
observation compartment).

The GOF plots look actually good, as far as I can see. However, you might
have right about that the simulation indicates deficiency of the model
rather then insufficient information given to NONMEM.

Regarding what I’m trying to do:
I’m doing a data-splitting analysis, where I’ve divided the dataset into
10 subsets. Each subset was analysed by NONMEM using the final model. This
was done in order to compare the parameter estimates with that of the
final model. All the values for the subsets were in the range of ± 2 SD.
Also I want to predict the concentrations in the remaining 10 % from each
of the 10 subsets using the estimates from each subset. This is what I
asked help for.

Thanks for your reply!


Live


Received on Fri Sep 21 2007 - 10:27:44 EDT