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Table 6 Impact of Percentage Missing Under Conditions 1, 2, and 3.

From: The use of complete-case and multiple imputation-based analyses in molecular epidemiology studies that assess interaction effects

a. Condition 1a

Scenario

Variable*

Method

Mean β

Mean SE

Mean Bias

MSE

RelMSE

Coverage

A1: 20% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.002

0.211

0.002

0.044

0.543

95.0 (93.6,96.4)

  

CC

1.000

0.284

-0.000

0.081

1.000

95.8 (94.6,97.0)

  

MI

1.062

0.230

0.062

0.052

0.644

95.9 (94.7,97.1)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.549

0.378

0.049

0.166

0.068

95.4 (94.1,96.7)

  

CC

2.713

4.822

0.213

2.436

1.000

97.0 (95.9,98.1)

  

MI

2.543

0.426

0.043

0.178

0.072

96.8 (95.7,97.9)

 

Interaction (True effect = 1.5)

Full

1.547

0.434

0.047

0.204

0.082

95.7 (94.4,97.0)

  

CC

1.713

4.894

0.213

2.503

1.000

96.7 (95.6,97.8)

  

MI

1.482

0.483

-0.018

0.205

0.082

96.1 (94.9,97.3)

A2: 30% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.003

0.211

0.003

0.044

0.358

94.6 (93.2,96.0)

  

CC

0.992

0.345

-0.008

0.122

1.000

95.0 (93.6,96.4)

  

MI

1.095

0.245

0.095

0.065

0.531

94.9 (93.5,96.3)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.558

0.379

0.058

0.146

0.014

97.2 (96.2,98.2)

  

CC

3.288

25.207

0.788

10.689

1.000

98.5 (97.7,99.3)

  

MI

2.557

0.462

0.057

0.178

0.017

98.3 (97.5,99.1)

 

Interaction (True effect = 1.5)

Full

1.555

0.435

0.055

0.195

0.018

96.1 (94.9,97.3)

  

CC

2.295

25.290

0.795

10.904

0.018

96.1 (94.9,97.3)

  

MI

1.462

0.515

-0.038

0.219

0.020

97.8 (96.9,98.7)

A3: 40% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.020

0.211

0.020

0.045

0.258

95.6 (94.3,96.8)

  

CC

0.991

0.411

-0.009

0.175

1.000

95.5 (94.2,96.8)

  

MI

1.137

0.263

0.137

0.083

0.474

94.1 (92.6,95.6)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.540

0.377

0.040

0.140

0.006

96.6 (95.5,97.7)

  

CC

4.121

64.794

1.621

23.920

1.000

96.5 (95.4,97.6)

  

MI

2.536

0.489

0.036

0.177

0.007

97.5 (96.5,98.5)

 

Interaction

(True effect = 1.5)

Full

1.520

0.433

0.020

0.191

0.008

96.0 (94.8,97.2)

  

CC

3.131

64.890

1.631

24.283

1.000

97.0 (95.9,98.1)

  

MI

1.399

0.538

-0.101

0.220

0.009

97.2 (96.2,98.2)

b. Condition 2b

Scenario

Variable

Method

Mean β

Mean SE

Mean Bias

MSE

RelMSE

Coverage

A4: 20% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.007

0.108

0.007

0.012

0.590

95.5 (94.2,96.8)

  

CC

1.010

0.147

0.010

0.021

1.000

95.9 (94.7,97.1)

  

MI

1.059

0.115

0.059

0.017

0.820

92.5 (90.9,94.1)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.552

0.279

0.052

0.089

0.909

93.7 (92.2,95.2)

  

CC

2.548

0.298

0.048

0.098

1.000

93.4 (91.9,94.9)

  

MI

2.593

0.281

0.093

0.095

0.966

94.5 (93.1,95.9)

 

Interaction

(True effect = 1.5)

Full

1.544

0.300

0.044

0.102

0.872

93.6 (92.1,95.1)

  

CC

1.538

0.332

0.038

0.117

1.000

94.0 (92.5,95.5)

  

MI

1.534

0.304

0.034

0.101

0.863

94.0 (92.5,95.5)

A5: 30% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.003

0.108

0.003

0.012

0.437

94.5 (93.1,95.9)

  

CC

1.008

0.168

0.008

0.027

1.000

94.6 (93.2,96.0)

  

MI

1.079

0.118

0.079

0.020

0.741

92.4 (90.8,94.0)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.532

0.277

0.032

0.078

0.798

95.7 (94.4,97.0)

  

CC

2.529

0.317

0.029

0.098

1.000

96.2 (95.0,97.4)

  

MI

2.612

0.284

0.112

0.091

0.928

95.6 (94.3,96.9)

 

Interaction

(True effect = 1.5)

Full

1.529

0.297

0.029

0.091

0.731

95.4 (94.1,96.7)

  

CC

1.521

0.359

0.021

0.125

1.000

94.8 (93.4,96.2)

  

MI

1.533

0.308

0.033

0.093

0.743

95.4 (94.1,96.7)

A6: 40% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.005

0.108

0.005

0.011

0.330

95.8 (94.6,97.0)

  

CC

1.007

0.197

0.007

0.035

1.000

95.9 (94.7,97.1)

  

MI

1.109

0.123

0.109

0.026

0.749

87.5 (85.5,89.5)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.551

0.279

0.051

0.081

0.620

95.7 (94.4,97.0)

  

CC

2.563

0.355

0.063

0.131

1.000

96.2 (95.0,97.4)

  

MI

2.675

0.295

0.175

0.112

0.852

94.3 (92.9,95.7)

 

Interaction

(True effect = 1.5)

Full

1.547

0.300

0.047

0.094

0.563

95.1 (93.8,96.4)

  

CC

1.557

0.406

0.057

0.168

1.000

95.3 (94.0,96.6)

  

MI

1.565

0.319

0.065

0.098

0.588

96.9 (95.8,98.0)

c. Condition 3c

Scenario

Variable

Method

Mean β

Mean SE

Mean Bias

MSE

RelMSE

Coverage

A7: 20% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.012

0.108

0.012

0.012

0.076

94.7 (93.3,96.1)

  

CC

0.616

0.119

-0.384

0.162

1.000

11.9 (9.9,13.9)

  

MI

0.999

0.109

-0.001

0.012

0.077

94.3 (92.9,95.7)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.549

0.279

0.049

0.080

0.667

96.1 (94.9,97.3)

  

CC

2.320

0.289

-0.180

0.120

1.000

87.1 (85.0,89.2)

  

MI

2.551

0.280

0.051

0.080

0.666

96.2 (95.0,97.4)

 

Interaction

(True effect = 1.5)

Full

1.537

0.300

0.037

0.091

0.635

96.1 (94.9,97.3)

  

CC

1.704

0.313

0.204

0.143

1.000

92.6 (91.0,94.2)

  

MI

1.552

0.301

0.052

0.092

0.642

95.7 (94.4,97.0)

A8: 30% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.006

0.108

0.006

0.012

0.027

95.0 (93.6,96.4)

  

CC

0.331

0.127

-0.669

0.466

1.000

0.3 (0,0.6)

  

MI

0.983

0.110

-0.017

0.013

0.028

95.0 (93.6,96.4)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.528

0.277

0.028

0.075

0.179

95.8 (94.6,97.0)

  

CC

1.927

0.299

-0.573

0.419

1.000

48.6 (45.5,51.7)

  

MI

2.492

0.277

-0.008

0.072

0.171

95.6 (94.3,96.9)

 

Interaction

(True effect = 1.5)

Full

1.522

0.297

0.022

0.084

0.743

96.0 (94.8,97.2)

  

CC

1.596

0.325

0.096

0.113

1.000

95.7 (94.4,97.0)

  

MI

1.509

0.298

0.009

0.081

0.713

96.1 (94.9,97.3)

A9: 40% missing

        
 

X1 (X2 = 0) (True effect = 1.0)

Full

1.007

0.108

0.007

0.011

0.012

95.8 (94.6,97.0)

  

CC

0.027

0.139

-0.973

0.966

1.000

0.0 (0.0,0.0)

  

MI

0.968

0.110

-0.032

0.013

0.013

94.1 (92.6,95.6)

 

X1 (X2 = 1) (True effect = 2.5)

Full

2.537

0.277

0.037

0.079

0.092

95.6 (94.3,96.9)

  

CC

1.627

0.312

-0.873

0.864

1.000

23.1 (20.5,25.7)

  

MI

2.461

0.276

-0.039

0.073

0.085

95.4 (94.1,96.7)

 

Interaction

(True effect = 1.5)

Full

1.531

0.298

0.031

0.089

0.683

96.1 (94.9,97.3)

  

CC

1.600

0.342

0.100

0.130

1.000

95.2 (93.9,96.5)

  

MI

1.493

0.297

-0.007

0.081

0.627

96.9 (95.8,98.0)

  1. Results From Fitting Full, Complete-Case, and Multiple Imputation Models to 1000 Simulated Data Sets With a Sample Size of 1000 Where the Covariate of Interest and as a Result the Interaction Term Were Missing for Some Subjects and the Auxiliary Information Was Strong.
  2. aCondition 1: X1 is 7.4 times more likely to be missing if X1 = 1, where X1 is binary
  3. bCondition 2: Extreme values of X1 are more likely to be missing (probability of missing is a quadratic function of X1 or the log odds of missing X1 = γ0+γ1 X1 + γ2 X12, where γ1 = -1 and γ2 = 2), where X1 is continuous
  4. cCondition 3: A 1-unit increase in X1 corresponds to a 7.4 times decrease in the probability of missing for controls, but a 7.4 times increase for cases, where X1 is continuous