RE: Is it reasonable to add covarite to PD parameters kin or kout?
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 is 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 observed value to
predict the parameters (which then predict the observed value). Also note that
covariates are, by definition, measured without error, and a baseline value is
likely measure with error (the same error as any other observation?).
Mark
Quoted reply history
From: [email protected] [mailto:[email protected]] On
Behalf Of Zhao,Li
Sent: Monday, July 27, 2015 2:39 PM
To: [email protected]
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 significant 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!