NONMEM Users Network Archive

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Re: Very small P-Value for ETABAR

From: Jian Xu <alanub>
Date: Thu, 13 Nov 2008 08:32:29 -0800 (PST)

Hi, Bill, Thanks for your input. I also got some answers from Mahesh, =
Yaning,  and Pankaj. Thank you guys! This small P-value for ETABAR c=
ould be due to possible two reasons: 1: As Bill and Yaning suggested, t=
his ETA is  non-nomal distribuated, which could result from covariates (e=
.g. gender) or mixture of population (e.g. race) 2: As Mahesh and Panka=
j suggested, the shrinkage of this ETA needs to be calculated, which can he=
lp identify whether the model is ill conditioning or overparameterized =
. Cheers, Jian   ______________________________=
__ From: "Denney, William S." <william_denney
8 10:41:15 AM Subject: RE: [NMusers] Very small P-Value for ETABAR =

om: owner-nmusers
ehalf Of Jian Xu Sent: Thursday, November 13, 2008 10:16 AM To: nmusers=
Dear NMUSERS, A few years back, there was a discussion on the P-value =
for ETABAR. However, I am not sure how to appropriately handle very small P=
-value(s) for ETABAR situation during the development of a model. I n=
eed some clarifications to a few questions: 1: Should we just ignore this=
 small P-Value warning? 2: Can we change IIV model to avoid small P-va=
lue for ETABAR? Or any other suggestions? 3: Does NONMEM make any assump=
tions on ETA distribution? This P-value for ETABAR really bugs me a lo=
t. I look forward to seeing some input. Thank you and I appreicate y=
our time and help. Jian Notice: This e-mail message, together wi=
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Received on Thu Nov 13 2008 - 11:32:29 EST

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