NONMEM Users Network Archive

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[NMusers] W for time varying covariates

From: Bernard Ngara <bernardngara4_at_gmail.com>
Date: Thu, 5 Oct 2017 15:38:53 +0200

Dear users

I was trying to fit a covariate model using SCM approach in PsN with the
code:

model = run1.mod
logfile=run1.log
search_direction = both
p_forward=0.05
p_backward=0.01
continuous_covariates=CD4,HWT,BWT,HT,BMI,AGE,TOAR,VAS
categorical_covariates=LNGTH,SEX,REGIMEN,CARE,EDU,WHO,BMI4AGE
time_varying =CD4,HWT,BMI,AGE,TOAR,VAS

[test_relations]
FOA=CD4,LNGTH,HWT,BMI,AGE,SEX,REGIMEN,TOAR,CARE,EDU,WHO,VAS,BMI4AGE
FOR=CD4,LNGTH,HWT,BMI,AGE,SEX,REGIMEN,TOAR,CARE,EDU,WHO,VAS,BMI4AGE


[valid_states]
continuous = 1,2
categorical = 1,2

The run fails and gives the following error message:

Starting scm forward search
Could not find assignment to W in $PRED needed for time_varying at
C:/Portable_PKPD/Perl/bin/..\site\lib\PsN_4_7_0/tool/scm.pm line 5764.

However I do have the W in the model file as:

IF(DVID.EQ.1) W=SIGMA(2,2) ;
IF(DVID.EQ.2) W=SIGMA(4,4)
IRES=IPRED-DV
IWRES=IRES/W

The baseline model runs well with stability and reasonable estimates of
parameters but I am facing a challange on implementing the SCM.

Kind regards

--
Bernard Ngara

Biostatistician
Harare
Zimbabwe
+263 776 971 400


Received on Thu Oct 05 2017 - 09:38:53 EDT

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