RE: 95% prediction interval and $OMEGA
Thank you very much for this suggestion. Unfortunately I am using NONMEM V
which does not have TRUE=FINAL option in $SIMULATION, but I will keep
exploring it.
Thanks!
Kelong Han
>
> Just to elaborate slightly on this last suggestion. If you use a $MSFI to
> input your parameters, use TRUE=FINAL to use the final, as opposed to the
> initial, estimates from that preceding run. If $MSFI is not used,
> TRUE=FINAL
> has no meaning.
>
> 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
> [EMAIL PROTECTED]
>
>
>
>
>
>
>
>
>
Quoted reply history
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On
> Behalf Of Mouksassi Mohamad-Samer
> Sent: Friday, June 06, 2008 22:14
> To: [EMAIL PROTECTED]; [email protected]
> Subject: RE: [NMusers] 95% prediction interval and $OMEGA
>
>
> Hello Kelong,
>
> Did you try to put TRUE=FINAL in the $simulation record.
>
> I suggest also to input you parameters using MSFI
>
> Bests,
>
> Samer
> -----Original Message-----
> From: [EMAIL PROTECTED] on behalf of Han, Kelong
> Sent: Thu 6/5/2008 21:49
> To: [email protected]
> Subject: [NMusers] 95% prediction interval and $OMEGA
>
> Dear NONMEM users,
>
> I am trying to calculate and plot the 95% prediction interval (PI) for a
> single-subject multiple-dosing PO dataset by simulating 1000 DV values.
>
> It seems that bigger initial estimate of omega ($OMEGA) leads to wider 95%
> prediction band. I understand that OMEGA directs the variability in
> "ERR(1)" in single-subject data, but I am still confused.
>
> Could anyone help me pick up a $OMEGA to calculate 95% PI, or solve this
> problem in another way? Thanks!
>
> Below is the control stream (the best-fit THETA values were used as
> initials):
>
> --------------------------------------------------
> $DATA po.csv IGNORE=C
>
> $INPUT ID TIME CONC=DV AMT MDV CMT
>
> $SUBROUTINE ADVAN2 TRANS2
>
> $PK
> CL = THETA(1)
> V = THETA(2)
> KA = THETA(3)
> S2 = V
> F1 = 1
>
> $ERROR
> IPRED=F
> Y=F+ERR(1)
>
> $THETA (0.398)
> $THETA (64.3)
> $THETA (0.425)
>
> $OMEGA 1.2
>
> $SIMULATION (324422) SUBPROBLEMS=1000
> $ESTIMATION METHOD=0 NOABORT MAXEVAL=9999 PRINT=0
> $COVARIANCE
> $TABLE TIME DV IPRED NOPRINT NOHEADER FILE=
> ---------------------------------------------------------
>
> Any input would be greatly appreciated.
>
> Thanks!
>
> Sincerely
> --
> Kelong Han
> PhD student
>
>
>
>