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RE: [NMusers] Extreme values of CWRESI in NONMEM 7.4.1?

From: Bauer, Robert <Robert.Bauer_at_iconplc.com>
Date: Tue, 21 Nov 2017 16:21:14 +0000

Hello all:
After working with Paolo Denti and Sven Stodtman, it has been determined that the occasional spurious CWRES and CWRESI values occurs during parallelization of the diagnostic evaluation step. The best work-around is to set the PARAFILE=OFF option on the first $TABLE record:

$TABLE … PARAFILE=OFF

This will allow $EST and $COV step to continue to be parallelized. Single CPU runs will of course not have this issue.


Robert J. Bauer, Ph.D.
Senior Director
Pharmacometrics R&D
ICON Early Phase
820 W. Diamond Avenue
Suite 100
Gaithersburg, MD 20878
Office: (215) 616-6428
Mobile: (925) 286-0769
Robert.Bauer_at_iconplc.com<mailto:Robert.Bauer_at_iconplc.com>
www.iconplc.com<http://www.iconplc.com/>

From: owner-nmusers_at_globomaxnm.com [mailto:owner-nmusers_at_globomaxnm.com] On Behalf Of Paolo Denti
Sent: Thursday, November 16, 2017 1:34 AM
To: nmusers
Subject: [NMusers] Extreme values of CWRESI in NONMEM 7.4.1?

Dear all,
I am reporting about a suspicious behaviour I am observing with CWRESI in NONMEM 7.4.1.

I have a patent/metabolite model which fits the data decently in terms of VPCs and other diagnostics, but the CWRESI have some EXTREME values (e.g. some are less than -15 and more than +40). After checking for outliers or mistakes in the dataset and finding no obvious reason for this, I realised something funny was happening.

For all those patients with extreme CWRESI values, all the CWRESI were exactly the same as WRES. I noticed that this happened for other subjects as well, without extreme values. In fact it was observed in a number of consecutive patients in the dataset, then the CWRESI and WRES were different once again for a number of IDs, then different again.
I pasted below the beginning of my output table (I hope it won't get horribly mangled in the email). You can see for ID 1002 things are fine, but for the next subject, all CWRESI and WRES are 100% the same, which I find very odd. Going on in the table, one then encounters the crazy values (e.g. +40) in those patients where CWRESI=WRES.

After thinking that I had messed up something in the code (although I have a fairly standard $ERR chunk), I reran the same models with NM 7.3 and no extreme CWRESI were to be seen and in no patient CWRESI=WRES. I tried ifortran and gfortran, same results.

Not sure if this is a bug or something has changed in the implementation of CWRESI in the new version? Anything that needs to be added into the code? Did anyone else experience something similar?

Thanks for sharing your experience,
Paolo
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Received on Tue Nov 21 2017 - 11:21:14 EST

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