RE: Truncated Emax
Hi Francois,
For pain measurements it is not uncommon to analyze data with a upper limit of
quantitation. You can follow the literature on BQL, only reversing from a lower
limit to an upper limIt. In my experience just deleting censored data works
fine, certainly as a first attempt, as long as censoring stays below ~1/3 of
total data.
Best regards,
Jeroen
J. Elassaiss-Schaap
Scientist PK/PD
MSD
PO Box 20, 5340 BH Oss, Netherlands
Phone: + 31 412 66 9320
Fax: + 31 412 66 2506
e-mail: [email protected]
Quoted reply history
________________________________
From: [email protected] [mailto:[email protected]] On
Behalf Of Francois Gaudreault
Sent: Monday, December 19, 2011 21:40
To: [email protected]
Subject: [NMusers] Truncated Emax
Dear NM users
I am currently developing a PK PD model for local anesthetics using a
sequential approach with ADVAN6. The PD model is a sigmoid Emax with an effect
compartment (Ce).
The intensity and duration of nerve blockade are monitored throughout the
perioperative period in patients using a quantitative pharmacodynamic endpoint,
i.e, the current perception threshold (CPT) REF: Can. J. Anesth, 57 (S1) 2010).
Briefly, CPT is evaluated before and after the administration of the local
anesthectic. Data are normalized by baseline using the following equation :
(observed-baseline) / (max-baseline) *100 (%)
Here is the problem. The device only goes to a maximum of 10 mA. In some
patients, the real Emax is much higher. Any ideas on how handle a truncated
Emax ?
Thanks in advance
--
François Gaudreault, Ph.D. Candidate
Pharmacométrie / Pharmacometrics
Charger de cours / Lecturer
Faculté de pharmacie / Faculty of Pharmacy
Université de Montréal
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