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RE: Is it reasonable to add covarite to PD parameters kin or kout?

From: Mark Sale <msale>
Date: Mon, 27 Jul 2015 19:33:47 +0000

Li,
I'm going to go out on a limb (since I haven't seen your data or understand=
 the biology) and suggest that the baseline value is not a covariate, but i=
s just another observation (presumably with drug concentration = 0). The=
 baseline value is sort of by definition a function of kin. So, you might =
look for predictors of Kin (age? Disease stage?) rather than using the obse=
rved value to predict the parameters (which then predict the observed value=
). Also note that covariates are, by definition, measured without error, a=
nd a baseline value is likely measure with error (the same error as any oth=
er observation?).

Mark



From: owner-nmusers
 Behalf Of Zhao,Li
Sent: Monday, July 27, 2015 2:39 PM
To: nmusers
Subject: [NMusers] Is it reasonable to add covarite to PD parameters kin or=
 kout?


Dear NMusers,



Right now I am doing covarite analysis for an indirect response model.



 I tested a few potential covarites and found it's STATISTICALLY significan=
t if I add observed baseline value to kin.



But I am not sure if it makes sense to add the baseline value as a covarite=
 to kin.



Could you please help me if you have had similar experiences before?



Thank you very much!

Received on Mon Jul 27 2015 - 15:33:47 EDT

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