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Table 4 Properties of point estimates of the treatment effect from Models A - E in scenarios 1 to 3

From: Comparing methods to estimate treatment effects on a continuous outcome in multicentre randomized controlled trials: A simulation study

  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 1 - balanced design, 45 centres each with 4 subjects
A 0.496
(0.148)
0.149 0.022 0.499
(0.146)
0.152 0.021 0.497
(0.151)
0.167 0.023
B 0.496
(0.148)
0.148 0.022 0.499
(0.146)
0.148 0.021 0.497
(0.151)
0.149 0.023
C 0.496
(0.148)
0.147 0.022 0.499
(0.146)
0.148 0.021 0.497
(0.151)
0.149 0.023
D 0.496
(0.148)
0.146 0.022 0.499
(0.146)
0.146 0.021 0.497
(0.151)
0.147 0.023
E-1 0.496
(0.494)
0.066 0.244 0.491
(0.454)
0.066 0.206 0.506
(0.447)
0.065 0.200
E-2 0.499
(0.163)
0.172 0.027 0.497
(0.166)
0.170 0.027 0.494
(0.162)
0.170 0.026
Scenario 2 - balanced design, 18 centres each with 10 subjects
A 0.490
(0.149)
0.150 0.022 0.504
(0.155)
0.152 0.024 0.498
(0.145)
0.166 0.021
B 0.490
(0.149)
0.149 0.022 0.504
(0.155)
0.149 0.024 0.498
(0.145)
0.149 0.021
C 0.490
(0.149)
0.148 0.022 0.504
(0.155)
0.148 0.024 0.498
(0.145)
0.149 0.021
D 0.490
(0.149)
0.142 0.022 0.504
(0.155)
0.143 0.024 0.498
(0.145)
0.142 0.021
E-1 0.490
(0.178)
0.130 0.032 0.501
(0.180)
0.130 0.032 0.498
(0.171)
0.130 0.029
E-2 0.492
(0.164)
0.154 0.027 0.503
(0.165)
0.155 0.027 0.498
(0.158)
0.153 0.025
Scenario 3 - balanced design, 6 centres each with 30 subjects
A 0.496
(0.149)
0.149 0.022 0.492
(0.149)
0.152 0.022 0.504
(0.151)
0.164 0.023
B 0.496
(0.149)
0.149 0.022 0.492
(0.149)
0.149 0.022 0.504
(0.151)
0.149 0.023
C 0.496
(0.149)
0.149 0.022 0.492
(0.149)
0.149 0.022 0.504
(0.151)
0.149 0.023
D 0.496
(0.149)
0.130 0.022 0.492
(0.149)
0.130 0.022 0.504
(0.151)
0.149 0.023
E-1 0.497
(0.153)
0.144 0.023 0.491
(0.154)
0.144 0.024 0.508
(0.156)
0.144 0.024
E-2 0.497
(0.151)
0.163 0.023 0.491
(0.151)
0.163 0.023 0.507
(0.153)
0.161 0.023
  1. SD: empirical standard deviation; Ave. SE: average estimated SE; MSE: mean squared error; ICC: intraclass (intracentre) correlation