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. Author manuscript; available in PMC: 2011 Oct 13.
Published in final edited form as: J Pharmacokinet Pharmacodyn. 2009 Jun 27;36(4):317–339. doi: 10.1007/s10928-009-9124-x

Table IV.

Published simulation studies evaluating the performances of tests on discrete covariate effect for differents designs using nonlinear mixed effects models. ANOVA, Student and Wilcoxon tests are based on empirical Bayes estimates of the individual parameters

First author (reference) Year Algorithm Software Number of PK parameters Design Test Covariate Type I error
Distribution (%) Effect
Bertrand (present study) 2009 SAEM MONOLIX 3 N={40,200}/n=4
N=80/n=2
N=100/n=4,1
ANOVA
Wald
LRT
24:48:28 1:1.2:1.6 No inflation for ANOVA
Slight inflation for Wald and LRT when N={40,80,100} corrected on N=200
Panhard1 (28) 2009 SAEM MONOLIX 3 N={40,24}/n=10 Wald
LRT
50:50 - No inflation
Bertrand (8) 2008 FO
FOCE-I
NONMEM 3 N={40,200}/n=4 ANOVA
Wald
LRT
24:48:28 1:1.2:1.6 No inflation for ANOVA
Strong inflation for Wald and LRT with FO when N={40,200}
Slight inflation for Wald and LRT when N=40 corrected on N=200 with FOCE-I
Samson (17) 2007 SAEM MONOLIX 4 N={40,80,200}/n=6 Wald
LRT
50:50 1:{1.3,1.5} No inflation
Panhard1 (36, 33) 2007/2005 FOCE-I R (nlme) 3 N=12/n=10
N=24/n=5
N=40/n=3
N={24,40,60}/n=10
Student
Wilcoxon
Wald
LRT
50:50 1:{0.8,0.875, 0.9,1.1, 1.125,1.25} Inflation for Student and Wilcoxon when n=3, but not for n={5,10}
Inflation for Wald and LRT when N={24,12}, but not for N=40
No inflation for Wald and LRT when modelling IOV
Bonate (31) 2005 FOCE NONMEM 2 All combinations of N={50,100,150,200}/n={2,4,6} ANOVA
LRT
50:50 1:1.25 No inflation for ANOVA
Inflation for LRT when n={4,6}
Zhang (45) 2003 FOCE-I NONMEM 4 N=30/n=5 LRT 50:50 - No inflation
Gobburu (30) 2002 FO
FOCE
FOCE-I
NONMEM 3 N=30/{n=5,2,(5,2)} LRT Continuous - Strong inflation with FO
Sligh inflation with FOCE when n={5,(5,2)}
No inflation with FOCE-I
Comets (32) 2001 FOCE
FOCE-I
NONMEM 3 N=20/n=7 Wilcoxon
LRT
50:50 1:1.2 No inflation for Wilcoxon (individual fits)
Inflation for LRT with FOCE
No inflation for LRT with FOCE-I
Lee (40) 2001 FOCE-I R (nlme) 3 N=200/n=2
N=100/n={2,3,(5,2)}
Student
LRT
90:10
80:20
70:30
60:40
50:50
1:1.3 Inflation for Student when n=5,2
Inflation for LRT when n={2,(5,2)}
Inflation increases when the proportion of the subpopulation increases
Wählby (29) 2001 FO
FOCE
FOCE-I
Laplacian
Laplacian-I
NONMEM 2 All combinations of N={10,25,50,250,1000}/n={2,4,19} LRT 98:2
90:10
75:25
33:33:33
- Strong inflation with FOCE and Laplacian, when n={4,19} and when N={10,25,50}/n=2 with addition of N={250}/n=2 for FO
Slight inflation with-I method, when N={10,25}
No impact of the covariate distribution, when N=50/n=2
White (39) 1992 FO NONMEM 2 All combinations of N={60,75,100}2/n={10,2} Wald
LRT
85:154
70:30
50:50
1:{0.9,0.8, 0.7,0.6} Inflation for both Wald and LRT on all designs
Inflation increases when n and/or the proportion of the subpopulation increases
1

Cross-over trials

2

The size of the control group remains 50, only the size of the comparison group varies