Dear NMusers,
I have a question also related to omega blocks. Would it be okay to
have two such blocks?
In my model for instance correlation between eta 1, 2, and 3 seem
biologically plausible, as is a correlation between eta 4 and 5.
Correlations between 1, 2, or 3 and eta 4 or 5 is high
...@otago.ac.nz]
Sent: Thursday, April 16, 2009 10:13 AM
To: Mats Karlsson; drmo...@pri-home.net; nele.pl...@nycomed.com;
nmusers@globomaxnm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
Mats
With oral data only I would normally model with BLOCK(2) on
CL/F and V/F or a DIAG(3) o
: Thursday, April 16, 2009 2:22 PM
To: Mats Karlsson
Cc: nmusers@globomaxnm.com
Subject: Re: [NMusers] OMEGA BLOCK with mixture model?
Mats,
Another difference between BLOCK(2) and DIAG(3) is that they provide
different number of ETAs for the individual fit. I am a bit surprised
that one-compartment
: Thursday, April 16, 2009 11:15 PM
To: Mats Karlsson; drmo...@pri-home.net; nele.pl...@nycomed.com;
nmusers@globomaxnm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
Mats
Thanks for your succinct summary.
For point 1. In a more general sense I think a covariance term can be
extracted from
Andreas,
Thanks for the suggestion. However, I think its only necessary to
enforce 0 to 1 boundaries on the individual value of F1 when one is
modelling absolute bioavailability.
In this example I gave the individual 'apparent' bioavailability can be
due to a variety of differences from the
Nick,
In your code example for the estimation of a 'relative bioavailability'
wouldn't it be necessary to use a logit transformation to keep F1 between 0
and 1? Something like: F1 = 1/(1+exp(BSV_F1))
Regards, Andreas.
Andreas Lindauer
Department of C
.karls...@farmbio.uu.se]
> Sent: Thursday, 16 April 2009 11:07 p.m.
> To: Stephen Duffull; drmo...@pri-home.net;
> nele.pl...@nycomed.com; nmusers@globomaxnm.com
> Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
>
> Hi Steve,
>
> For a one-compartment model I think these are diffe
t; nele.pl...@nycomed.com;
nmusers@globomaxnm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
Mats
With oral data only I would normally model with BLOCK(2) on
CL/F and V/F or a DIAG(3) on CL/F, V/F and relative F. The
latter may have some advantages for diagnostics, covariate
model buildin
rmo...@pri-home.net; nele.pl...@nycomed.com;
nmusers@globomaxnm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
Mats
> With oral data only I would normally model with BLOCK(2) on
> CL/F and V/F or a DIAG(3) on CL/F, V/F and relative F. The
> latter may have some advantages for dia
Mats
> With oral data only I would normally model with BLOCK(2) on
> CL/F and V/F or a DIAG(3) on CL/F, V/F and relative F. The
> latter may have some advantages for diagnostics, covariate
> model building etc.
I have often seen these two options considered. I am unclear as to the
advantages of
P/alt...@altana-mail,
nmusers@globomaxnm.com
cc
Subject
RE: [NMusers] OMEGA BLOCK with mixture model?
Hi Diane,
With oral data only I would normally model with BLOCK(2) on CL/F and
V/F or a DIAG(3) on CL/F, V/F and relative F. The latter may have some
advantages fo
.com
cc
Subject
RE: [NMusers] OMEGA BLOCK with mixture model?
Hi Diane,
With oral data only I would normally model with BLOCK(2) on CL/F and V/F or a
DIAG(3) on CL/F, V/F and relative F. The latter may have some advantages for
diagnostics, covariate model building etc
d: Charles Depasse
Management Board: Dr. Barthold Piening, Gilbert Rademacher, Dr. Anders
Ullman
mats.karls...@farmbio.uu.se
16.04.2009 09:05
To
drmo...@pri-home.net, Nele Plock/DEKON/AP/alt...@altana-mail,
nmusers@globomaxnm.com
cc
Subject
RE: [NMusers] OMEGA BLOCK with mixture model?
7;Mats Karlsson'; nele.pl...@nycomed.com; nmusers@globomaxnm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
Dear All
I am not sure if this topic has been covered before or not, but as its
related to the question below, I thought I would bring it up again.
I have to wonder at th
Ullman
drmo...@attglobal.net
15.04.2009 18:16
Please respond to
drmo...@pri-home.net
To
mats.karls...@farmbio.uu.se, Nele Plock/DEKON/AP/alt...@altana-mail,
nmusers@globomaxnm.com
cc
Subject
RE: [NMusers] OMEGA BLOCK with mixture model?
Dear All
I am not sure if this topic has been
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: [NMusers] OMEGA BLOCK with mixture model?
Dear Nele,
I think you may want to reconsider your model. If you have a negative
correlation between CL and F1, it is likely to be related to high
presystemic metabolism (first-pass) effect. If so, it seems strange to
assume that the F1
nm.com
Subject: RE: [NMusers] OMEGA BLOCK with mixture model?
If you want both CL1 and CL2 to be correlated with F (i.e. allow
Omega(CL1,F) and Omega(CL2,F) to be free in
the objective function optimization),
then I don't think there is any simple reordering of the random effects
that wil
April 15, 2009 6:6 AM
To: nele.pl...@nycomed.com
Cc: nmusers@globomaxnm.com
Subject: Re: [NMusers] OMEGA BLOCK with mixture model?
Nele,
going by the nonmem user manual, part VIII, p 94 ($OMEGA), "If FIXED appears
anywhere among the list of values, the entire block is fixed."
I did n
Hi,
It is indeed a nuisance to have to renumber all the ETAs if you have a
complex model and you change the sequence of $OMEGA.
You can of course choose to use the awk script which comes with WFN
(http://wfn.sourceforge.net) translate an extended NM-TRAN control
stream, which uses parameter
Nele,
going by the nonmem user manual, part VIII, p 94 ($OMEGA), "If FIXED
appears anywhere among the list of values, the entire block is fixed."
I did not see anyone pointing that out yet.
This does in fact imply that you need to reorder the sequence of random
effects (which can be quite a nu
Dear Nele,
I think you may want to reconsider your model. If you have a negative
correlation between CL and F1, it is likely to be related to high
presystemic metabolism (first-pass) effect. If so, it seems strange to
assume that the F1 distribution would not change between the two
subpopulatio
This should do the trick (rename ETAs):
$OMEGA BLOCK(3)
0.1 ;CL1
0.01 0.1 ;F1
00.01 0.1 ;CL2
(do not FIX anything)
Although I am not sure whether you need to estimate F1 for oral data
(without IV). You could try to use ETA on V instead of ETA on F1.
Leonid
-
Dear Nele,
To figure out the error of NONMEM, you can change the sequence of your
OMEGAs,
$OMEGA BLOCK(3)
0.1 ;CL1
0.01 0.1 ;F1
0 0.01 0.1 ;CL2
Make the corresponding change in the $PK block.
Regards,
Chenguang
2009/4/14
>
> Dear all,
>
> I am trying to f
Nele, You'll need to rearrange/reassign your ETAs so that you can have correlation between CL(1) and F1, and CL(2) and F1, but not CL(1) and CL(2). So, put ETA(1) on CL(1), ETA(2) on F1 and ETA(3) on CL(2), then $OMEGA like this:$OMEGA BLOCK(3) 0.1 ;CL(1) 0.01 0.1
Hi Nele,
About the technical issue, just change the order of your etas (2 and 3) in
order to have the 0 FIX at the place of cov1-3, this gives you what is
called a band matrix.
Hope it will help!
Best regards,
Elodie
Elodie L. Plan, PharmD, MSc,
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