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Hi All,
I am doing some data analysis by winnonlin for preclinical studies, my
knowledge is just preliminary in these types of calculation.
Noncompartmental analysis to calculate AUC from 2.5 mins to 8.00hrs.
a) I have 3 animal data: I calculated individual set of data and
average the AUC's of individual AUC's
b) Then I average the time point concentrations and calcualte only one
AUC which came out different from the average of individual AUC's.(a)
We have some conversation in our group (who are not pharmacokinetists)
which one is more acceptable.
Please give some advise and thanks in advance.
Lourdes
Santa Clara.
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Dear Mr. Lourdes Thevanayagam,
Can you please give details regarding the percentage of variation you
are getting between the two values
Regards,
Ravi kanth
Ravi Kanth Bhamidipati
Senior Pharmacologist
Dept.of Drug Metabolism and Pharmacokinetics
Discovery Research Division
Dr.Reddy's Laboratories Ltd.
Bollaram Road , Miyapur
Hyderabad - 500 050
Andhra Pradesh
India
It is better to average individual AUC.Back to the Top
Dear Ravi,Back to the Top
Thanks for your reply:
Average of the individual AUC's = 26918 hr.ng/ml
Averaging the concentrations and then one single AUC = 35184 hr. ng/ml
Thanks
Lourdes
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Hi Dr. Thevanayagam,
I think it is more appropriate to calculated individual set of data and
then
average the individual AUC's. This way you can also have some idea
about its
interindividual variability.
Best wishes,
Qi Liu
PO BOX 100494
Department of Pharmaceutics
College of Pharmacy
University of Florida
Gainesville, FL32610
Tel: (352)8463257 (work)
(352)8465225 (home)
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Hi Qi,
The Bootstrap can be used to provide confidence
intervals and standard error estimates for the AUC.
Here is a useful link for this purpose.
http://www.accumetric.com/bootlong.htm
Two books I find of use are:
Manly, B.F.J. (1997). Randomization, Bootstrap and
Monte Carlo Methods in Biology. New York: Chapman &
Hall.
Efron, B., and Tibshirani, R.J. (1993). An
Introduction to the Bootstrap. New York: Chapman &
Hall.
Hope this helps.
Paul Johnson
http://www.biostatsoftware.com
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Hi Qi,
The Bootstrap can be used to provide confidence
intervals and standard error estimates for the AUC.
Here is a useful link for this purpose.
http://www.accumetric.com/bootlong.htm
Two books I find of use are:
Manly, B.F.J. (1997). Randomization, Bootstrap and
Monte Carlo Methods in Biology. New York: Chapman &
Hall.
Efron, B., and Tibshirani, R.J. (1993). An
Introduction to the Bootstrap. New York: Chapman &
Hall.
Hope this helps.
Paul Johnson
http://www.biostatsoftware.com
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Hi, there!
Paul Johnson wrote
"Hi Qi,
The Bootstrap can be used to provide confidence
intervals and standard error estimates for the AUC.
Here is a useful link for this purpose.
http://www.accumetric.com/bootlong.htm
"
Well, the above link is dedicated to ROC AUC problem, which is
different from AUC of C-t profile in PK. Nonetheless, the bootsrap may
be useful in this context, see e.g..: Mager H., Goeller G: Analysis of
pseudo-profiles in organ pharmacokinetics and toxicokinetics.
Statistics in Medicine, 14, 1009-1024 (1995).
This paper may be even more important in the context of another thread
(Bailer Satterthwite AUC...).
"Two books I find of use are:
Manly, B.F.J. (1997). Randomization, Bootstrap and
Monte Carlo Methods in Biology. New York: Chapman &
Hall.
Efron, B., and Tibshirani, R.J. (1993). An
Introduction to the Bootstrap. New York: Chapman &
Hall.
"
The books are still useful, I believe.
Regards
Wojciech Jawien
Faculty of Pharmacy, Jagiellonian Univ.
ul. Medyczna 9
30-688 Krakow
Poland
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Dear Dr. Johnson,
Yes, I definitely agree with you that bootstrap can be used to get
better
estimation on variance.
However, since there are only 3 rats in the experiment, people still
need to
be very careful about the interpretation of the result. That is why I
said only
"...some idea about its interindividual variability". The results from
only 3
rats may not represent well the whole population, even bootstrap can
not help
much on that.
Thanks for the suggestions.
Best wishes,
Qi
Hi All,Back to the Top
Thank you very much for your input regarding my AUC calculations and
appreciate each and everyone for the continued support.
Best regards
Lourdes
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