Table 6 Properties of point estimates of the treatment effect from Models A - E in scenarios 4 to 6

ICC = 0.01 ICC = 0.05 ICC = 0.20
Model Mean
effect
(SD)
Ave.
SE
MSE Mean
effect
(SD)
Ave.
SE
MSE Mean
effect
(SD)
Ave.
SE
MSE
Scenario 4 - chance imbalance, 45 centres each with 4 subjects
A 0.502
(0.146)
0.150 0.021 0.511
(0.154)
0.154 0.024 0.494
(0.168)
0.166 0.028
B 0.506
(0.162)
0.172 0.026 0.510
(0.174)
0.172 0.030 0.496
(0.180)
0.172 0.032
C 0.502
(0.145)
0.149 0.021 0.511
(0.155)
0.152 0.024 0.496
(0.165)
0.159 0.027
D 0.501
(0.146)
0.146 0.021 0.511
(0.155)
0.149 0.024 0.496
(0.165)
0.155 0.027
E-1 0.492
(0.525)
0.122 0.275 0.504
(0.544)
0.126 0.296 0.481
(0.482)
0.127 0.232
E-2 0.506
(0.274)
0.265 0.075 0.515
(0.284)
0.269 0.081 0.490
(0.285)
0.260 0.081
Scenario 5 - chance imbalance, 18 centres each with 10 subjects
A 0.495
(0.148)
0.150 0.022 0.498
(0.150)
0.153 0.023 0.497
(0.169)
0.166 0.028
B 0.494
(0.156)
0.157 0.024 0.498
(0.152)
0.157 0.023 0.500
(0.161)
0.157 0.026
C 0.495
(0.148)
0.150 0.022 0.498
(0.149)
0.151 0.022 0.499
(0.159)
0.153 0.025
D 0.494
(0.148)
0.142 0.022 0.498
(0.150)
0.144 0.022 0.499
(0.159)
0.148 0.025
E-1 0.488
(0.206)
0.130 0.042 0.498
(0.199)
0.130 0.039 0.503
(0.204)
0.130 0.042
E-2 0.490
(0.177)
0.163 0.031 0.501
(0.172)
0.162 0.030 0.501
(0.178)
0.164 0.032
Scenario 6 - chance imbalance, 6 centres each with 30 subjects
A 0.499
(0.153)
0.149 0.023 0.502
(0.150)
0.153 0.022 0.510
(0.165)
0.164 0.027
B 0.499
(0.155)
0.150 0.024 0.501
(0.150)
0.151 0.022 0.507
(0.151)
0.152 0.023
C 0.499
(0.153)
0.149 0.024 0.503
(0.149)
0.150 0.022 0.507
(0.151)
0.151 0.023
D 0.498
(0.154)
0.129 0.024 0.503
(0.150)
0.131 0.022 0.508
(0.151)
0.134 0.023
E-1 0.498
(0.159)
0.146 0.025 0.502
(0.156)
0.146 0.024 0.507
(0.157)
0.146 0.025
E-2 0.498
(0.157)
0.165 0.025 0.502
(0.153)
0.164 0.023 0.507
(0.154)
0.167 0.024
1. SD: empirical standard deviation; Ave. SE: average estimated SE; MSE: mean squared error; ICC: intraclass (intracentre) correlation