NONMEM Users Network Archive

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RE: Stepwise covariate modeling

From: Luann Phillips <Luann.Phillips>
Date: Tue, 29 Oct 2019 15:00:50 +0000


If all of the individual predictions are the same for the model with the co=
variate and without the covariate, then it sounds like the original model i=
s at a local minimum instead of a global minimum.

Best regards,

From: owner-nmusers
 Of Singla, Sumeet K
Sent: Tuesday, October 29, 2019 10:00 AM
To: nmusers
Subject: [NMusers] Stepwise covariate modeling


I am performing stepwise covariate modeling using PsN feature in Pirana. I =
am getting some covariates which are statistically reducing OFV significant=
ly, however, when I include those covariates in the PK model, the results I=
 am getting are exactly similar to what I am getting in my base model, i.e.=
 there is no difference in individual predictions or pop predictions or any=
 other diagnostic plots. So, does that mean I should move forward WITHOUT i=
ncluding those covariates as they don't seem to be explaining inter-individ=
ual variability despite scm telling me that they are statistically signific=


Sumeet K. Singla
Ph.D. Candidate
Division of Pharmaceutics and Translational Therapeutics
College of Pharmacy | University of Iowa
Iowa City, Iowa

Received on Tue Oct 29 2019 - 11:00:50 EDT

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