Re: Problem with estimating sigma when using M3 method
you should fix
$SIGMA
1 FIX
as you are already estimating the SD using THETA(8).
Leonid
Quoted reply history
On 5/26/2023 4:57 AM, Hiba Sliem wrote:
> Hello
>
> I’m fairly new to nonmem, I’m currently trying to model a phase 1 study with BLQ values, while the run was successful with no error message, my residual error has a %rse >70 and a confidence interval that includes zero.
>
> Here’s my code:
>
> $ERROR
>
> LOQ=0.1
>
> IPRED = F
>
> SD = THETA(8)*IPRED
>
> DEL = 0
>
> IF(SD.EQ.0) DEL = 1
>
> IRES = DV - IPRED
>
> IWRES = IRES / (SD + DEL)
>
> DUM = (LOQ -IPRED) / (SD + DEL)
>
> CUMD = PHI(DUM) + DEL
>
> IF(BLQ.EQ.0) THEN
>
> F_FLAG=0
>
> Y= IPRED +SD*ERR(1)
>
> ELSE
>
> F_FLAG=1
>
> Y=CUMD
>
> MDVRES = 1
>
> ENDIF
>
> $EST METHOD=1 INTERACTION LAPLACIAN PRINT=5 MAX=9999 SIG=3 SLOW NUMERICAL MSFO=*.msf
>
> $SIGMA
>
> 0.38 ;[P] sigma(1,1) (estimated in a previous model)
>
> Furthermore, when trying to fit this model to my phase 2 dataset, covariance step fails when I implement it.
>
> Any suggestions are welcome
>
> Thank you