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Table 1 Varying and fixed parameters of simulated datasets that were used to compare the performance measures of different models

From: A comparison of the statistical performance of different meta-analysis models for the synthesis of subgroup effects from randomized clinical trials

Parameters

Value in simulation

Statistical notation in the linear predictor used for simulation of datasetb

Varying-parameters

 Number of trials

6, 10, 16, 20, 26, 30, 40, 50

 Magnitude of the interaction effecta

0, −0.01

beta.inter

 Between-trial variance of the interaction effecta

0, 0.005, 0.05, 0.5

V 2

Fixed-parameters

 Number of patients included in each trial

between 30 and 199 patients in small trials, and 200 and 400 patients in large trials

j

 Ratio of small to large trials

1:1

 Number of trial arms

2

treat

 Ratio of randomization

1:1

 Magnitude of the treatment effecta

−1

beta.treat

 Between-trial variance of the treatment effecta

0.063

V 1

 Effect of age on the outcome

0.05

age

 Random intercept variance

0.25

σ 2

 Random slope variance

0.04

τ 2

 Correlation between random intercept and random slope variances

0.8

ρ

 Age of individual patients

N(mean. age, variance. age)

age

 Mean age of patients within trials

N(67,20.25)

mean. age

 Variance of age within trials

N(49, 1)

variance. age

  1. aOn a 0 to 10 visual analogue scale
  2. bSee Eq. 4.1