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Table 1 Impact of sample size.

From: Performance of mixed effects models in the analysis of mediated longitudinal data

Simulated Data

Mediated SEM

LMM with Mediator as Covariate LMM1

LMM without Mediator LMM2

Sample Size

Bias (%)

Coverage Probability (%)

Power (%)

Bias (%)

Coverage Probability (%)

Power (%)

Bias (%)

Coverage Probability (%)

Power (%)

25

1.5

92

26

-48

85

14

2.1

91

26

50

1.5

93

41

-49

84

16

2.0

93

42

100

1.2

94

65

-49

75

26

1.7

94

65

200

-1.2

96

91

-51

56

41

-1.1

95

89

250

-1.6

94

95

-52

48

47

-1.6

93

94

500

-1.0

95

100

-51

21

78

-1.0

95

100

  1. Impact of sample size on model performance in evaluating the total effect of the main independent variable on random intercept.
  2. Based on 1000 simulated datasets with medium effect size equally distributed between direct and indirect effects.