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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