Dear nmusers:
I am providing instructions and examples of how to model individual parameters
with gamma distribution among the population in NONMEM. A general method for
modeling other distributions is also given. This material is located at (start
with the instruction file gamma_indpar.pdf):
https://nonmem.iconplc.com/nonmem/gamma_indpar
Robert J. Bauer, Ph.D.
Senior Director
Pharmacometrics R&D
ICON Early Phase
731 Arbor way, suite 100
Blue Bell, PA 19422
Office: (215) 616-6428
Mobile: (925) 286-0769
[email protected]<mailto:[email protected]>
http://www.iconplc.com/
Modeling for non-Normal distributions of individual parameters
Hi Bob,
Thanks for the instructions, it is very helpful. From the practical standpoint, using gamma as you described is somewhat complicated while using square-normal is trivial. Would it be a fair summary to say that:
-if the results of log-normal and square are similar (or if log-normal is better), we can stay with log-normal;
-if square-normal is much better then log-normal, then we should use square;
-gamma version provides only minor or no improvement versus square-normal and only when variances are large.
Thank you
Leonid
Quoted reply history
On 1/3/2023 11:49 AM, Bauer, Robert wrote:
> Dear nmusers:
>
> I am providing instructions and examples of how to model individual parameters with gamma distribution among the population in NONMEM. A general method for modeling other distributions is also given. This material is located at (start with the instruction file gamma_indpar.pdf):
>
> https://nonmem.iconplc.com/nonmem/gamma_indpar < https://nonmem.iconplc.com/nonmem/gamma_indpar >
>
> Robert J. Bauer, Ph.D.
>
> Senior Director
>
> Pharmacometrics R&D
>
> ICON Early Phase
>
> 731 Arbor way, suite 100
>
> Blue Bell, PA 19422
>
> Office: (215) 616-6428
>
> Mobile: (925) 286-0769
>
> [email protected] <mailto:[email protected]>
>
> www.iconplc.com http://www.iconplc.com/
>
>
Hello Leonid:
Yes, that is a fair general summary, with the usual caveat that the modeler
should decide what is best for the particular data at hand.
Robert J. Bauer, Ph.D.
Senior Director
Pharmacometrics R&D
ICON Early Phase
731 Arbor way, suite 100
Blue Bell, PA 19422
Office: (215) 616-6428
Mobile: (925) 286-0769
[email protected]<mailto:[email protected]>
http://www.iconplc.com/
Quoted reply history
From: Leonid Gibiansky <[email protected]>
Sent: Tuesday, January 3, 2023 6:47 PM
To: Bauer, Robert <[email protected]>; '[email protected]'
<[email protected]>
Subject: [EXTERNAL] Re: [NMusers] Modeling for non-Normal distributions of
individual parameters
Hi Bob,
Thanks for the instructions, it is very helpful. From the practical
standpoint, using gamma as you described is somewhat complicated while
using square-normal is trivial. Would it be a fair summary to say that:
-if the results of log-normal and square are similar (or if log-normal
is better), we can stay with log-normal;
-if square-normal is much better then log-normal, then we should use square;
-gamma version provides only minor or no improvement versus
square-normal and only when variances are large.
Thank you
Leonid