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[NMusers] Problem of STS in NONMEM

From: Anyue Yin <anyueyin929_at_gmail.com>
Date: Tue, 22 Dec 2015 14:36:09 +0800

Dear all,

I got a problem when using NONMEM with STS method. My aim is to get
individual parameter estimates. I would like to let NONMEM estimate
individual parameter one subject by one subject. My control stream is
partially listed below, which is edited according to this thread
http://www.cognigencorp.com/nonmem/nmo/topic035.html

*$SUBROUTINES ADVAN1 TRANS2*

*$PK*
*CL = THETA(1) * EXP(ETA(1))*
*V = THETA(2) * EXP(ETA(2))*
*S1 = V*

*$ERROR*
*IPRED = F*
* W = F*
* Y = IPRED*(1+EXP(ETA(3))*EPS(1))*
* IRES = DV-IPRED*
*IWRES = IRES/W*

*$THETA*
*(10,20,30) ; CL*
*(10,80,100) ; V*

*$OMEGA*
*100 ; IIV CL*
*100 ; IIV V*
*100 ; IIV SIGMA*

*$SIGMA*
*1 FIXED ; PRO*
*$EST METHOD=1 INTER MAXEVAL=0 NOABORT SIG=3 PRINT=1 POSTHOC*
*$COV*
*$TABLE ID TIME AMT CMT DV PRED IPRED IWRES CL V ETA(1) ETA(2) ETA(3)
ONEHEADER NOPRINT FILE=sdtab101.tab*

The model can run successfully, and I got individual parameter estimates
from output file. I found that for each subject the individual parameter
estimate changed if I change the initial value of THETA. It seems that
NONMEM regarded the initial value fixed (just like a fixed typical value).
But I expected NONMEM to estimate individual parameters based on individual
data rather than the initial value. Is there anything wrong with the code?
Thanks in advance.

Anyue

Received on Tue Dec 22 2015 - 01:36:09 EST

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