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Re: NONMEM code for Mixture Model

From: nidal.alhuniti
Date: Thu, 12 Mar 2009 15:44:58 -0400

Hi Huali,

You could use $MIX. Please see the NM help files for $MIX. You have to
specify the number of populations (in your case 2) so



$MIX

    NSPOP=2

    P(1)=THETA(4)

    P(2)=1.-THETA(4)



Then use

EST= MIXEST



Hopefully this helps.

Best,

Nidal



Nidal AL-Huniti, PhD

Associate Director, Modeling and Simulations

ICON Development Solutions SM


On 3/12/09, Huali Wu <hualiw
>
> Dear NMusers:
>
> I am working on dataset with high variability on clearance and patients in
> different disease states seems have different distribution of clearance. So
> I want to try the mixture model but I don't know how to do the coding. I
> listed the code of my base model as below:
>
> $PROB 1hr IV INFUSION SINGLE DOSE WITHOUT COVARIATES
> $DATA data01.CSV IGNORE=C
> $INPUT ID TIME DV AMT RATE MDV
>
> $SUBROUTINES ADVAN9 TRANS1 TOL=5
> $MODEL NPAR=3, NCOMP=1, COMP=(CENTRAL,DEFOBS)
>
> $PK
> V1 = THETA(1)*EXP(ETA(1))
> VM = THETA(2)*EXP(ETA(2))
> KM = THETA(3)
>
> S1 = V1
>
>
> $ERROR
>
> Y=F+F*EPS(1)+EPS(2)
>
> IPRED=F
> IRES=DV-IPRED
> IF(AMT.NE.0)W=1
> IF(AMT.EQ.0)W=F
> IWRES=IRES/W
>
> $DES
> C1 = A(1)/V1
> DADT(1) = - C1*VM/(KM+C1)
>
>
> $THETA (0, 4.47) (0, 155) (0, 1380)
> $OMEGA BLOCK (2)
> 0.5
> 0.3 0.9
>
> $SIGMA (0.01) (0.1)
>
> $EST POSTHOC METHOD=1 MAXEVAL=9990 PRINT=5
> $COV
> $TABLE ID TIME DV AMT RATE V1 VM KM IWRES IPRED NOPRINT FILE=TAB4
> ONEHEADER
> $SCAT (RES WRES) VS TIME BY ID
>
> Any suggestion will be highly appreciated!
>
> Best regards,
>
> Huali
>
>
>

Received on Thu Mar 12 2009 - 15:44:58 EDT

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