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Hi,
I would like to survey and get a feedback from the PK community
regarding the frequency of use of the Sparse data analysis Method
available in WNL to calculate the AUC for non clinical sparse studies.
Are you using it and if yes are you using it for regulatory studies.
Thank you for your help
Pascal
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Hi pascal,
I rarely used the sparse data analysis from WinNonlin. I usually take
mean of the data and go for analysis. I found no major difference for
routine preclinical PKs.
Others can comment...
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Hi
Sparse data analysis method can be used for non clinical regulatory
studies
Dr.Rajasekhar
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Just a couple of notes about this, it was originally implemented at
customers request as part of Pharsight's ongoing efforts to improve and
enhance the software. The method uses the following references, as
detailed in the help file;
Nedelman and Jia (1998). An extension of Satterthwaite's approximation
applied to pharmacokinetics. J Biopharm Stat 8(2):317-28.
Holder (2001). Comments on Nedelman and Jia's extension of
Satterthwaite's approximation applied to pharmacokinetics. J Biopharm
Stat 11(1-2):75-9.
It has certain advantages over just using a simple mean of the
raw concentrations in that it will calculate standard error for the mean
concentration curve's maximum value (Cmax), and for the area under the
mean concentration curve from dose time through to the final observed
time i.e. (AUClast)
Standard error of the mean Cmax will be calculated as the sample
standard deviation of the y-values at time Tmax divided by the square
root of the number of observations at Tmax.
Standard error of the mean AUC will be calculated as described in
Nedelman and Jia (1998), using a modification in Holder (2001), and will
account for any correlations in the data resulting from repeated
sampling of individual animals.
That said, I too would be interested to hear confirmation of any
regulatory submissions using this implementation in WinNonlin - or
indeed any further suggestions for enhancements.
Best regards,
Simon.
--
Simon Davis
Senior Scientific Consultant
http://www.linkedin.com/in/simondavis
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Is/Are there any other accepted PK/PD programs-Scientist/Mathcad/
Watson PK
Module/MINTAB that are any where close to Pharsight's hold?
Ed F. O'Connor,PhD
78 Marbern Drive
Suffield, CT 06078-1533
email: efoconnor.aaa.cox.net
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Sure ACSLX can do any of these things?
Lynne
AEgis Technologies Group
www.acslx.com
lhousand.aaa.acslx.com
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Pascal,
We use the sparse method to support GLP studies. For one observation
per animal design such as a typical toxicokinetic study with rodents,
this is probably the best choice. As mentioned by Simon, the
estimation of SEs of those PK parameters (Cmax, AUClast) is a pretty
good feature.
Jun
--
Jun Shen
PK/PD Scientist
BioPharma Services
Millipore Corporation
15 Research Park Dr.
St Charles, MO 63304
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I have used the Sparse button, often for samples taken from pharmacology
studies, since I learned about it on this forum. I also asked about a
geometric alternative before I realised that with sparse data there are
very often zero values and positive values at the same timepoint (and I
mean zero as in no peak at all, notthat have to be made in NCA, the Sparse Sampling method provides some
statistics where otherwise there would be almost none.
I use it mainly for discovery studies, but I don't see why it couldn't
be used for submissions. I have a general concern about Cmax in sparse
data sets; when Tmax is highly variable, the mean-data-at-timepoints
method underestimates Cmax and the Sparse method will overestimate the
s.e.m. on Cmax. Modelling would be better if there are enough data.
Ted
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