Re: non-linear PK
From: Leonid Gibiansky leonidg@metrumrg.com
Subject: Re: [NMusers] non-linear PK
Date: Thu, 06 Oct 2005 13:20:13 -0400
Ken,
Note that data are log-transformed. See
http://www.cognigencorp.com/nonmem/nm/99apr232002.html
for Mats Karlsson explanation how to apply combined error in the log-transformed case.
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To get the same error structure for log-transformed data as the
additive+proportional on the normal scale, I use
Y=LOG(F)+SQRT(THETA(x)**2+THETA(y)**2/F**2)*EPS(1)
with
$SIGMA 1 FIX
THETA(x) and THETA(y) will have the same meaning as on the untransformed scale
with
Y=F+SQRT(THETA(y)**2+THETA(x)**2*F**2)*EPS(1)
with
$SIGMA 1 FIX
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Leonid