RE: categorical covariate with 5 levels
I have a four levels covariate model. Hope this is useful to you.
Sam Liao
Pharmax Research
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RA1=0
RA2=0
RA3=0
IF(RACE.EQ.7) RA1=1
IF(RACE.EQ.8) RA2=1
IF(RACE.GT.8) RA3=1
TVCL= TVCL *(1 + THETA(33)*RA1+ THETA(34)*RA2+ THETA(35)*RA3)
Quoted reply history
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Hong Li
Sent: Thursday, July 08, 2010 9:01 PM
To: [email protected]
Subject: [NMusers] categorical covariate with 5 levels
Dear all,
I want to build a covariate model for the pk of a drug which is metabolized in
the liver. One of the covariates is liver GVHD which has 5 levels (
0,1,2,3,4). The only way I can think of is to group liver GVHD into two
categories, 0 ( not GVHD) and 1 ( having GVHD).
But there is interest to evaluate the effect of degree of GVHD on pk
parameter, e.g. CL.
Does anyone have any suggestions on building a categorical covariate model of
more than two levels. Thanks for any input.
Best regards,
Hong Li, Ph.D.
Postdoctoral Associate
Department of Pharmaceutical Science
University at Buffalo, SUNY
363 Hochstetter Hall
Buffalo, NY 14260
Tel#: (716)645-4827