RE: Plcebo Corrected PK/PD

From: "Bachman, William (MYD)" bachmanw@iconus.com Subject: RE: [NMusers] Plcebo Corrected PK/PD Date: Wed, March 2, 2005 1:05 pm Manoj, In a nutshell, averaging and baseline subtraction are probably the worst way to model placebo effect. Particularly when the response in absence of drug is not a "flat line". I'll let the statisticians give all the details but basically, averaging of anything removes information from the data and baseline subtraction has it's own issues. That being said, its often done (and in best case scenarios it may be a good first approximation but not ideal.) There are any number of examples out there of better approaches to accounting for placebo effect - the first two that come to mind are (1) Nick Holford's tacrine model and (2) Bill Jusko's cortisol papers that take into account circadian rhythm. Bill