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Table 2 Evaluation of OW and FS methods by simulation with the constant true effect by outcome risk along with observed/simulated exposure

From: Comparison of two propensity score-based methods for balancing covariates: the overlap weighting and fine stratification methods in real-world claims data

Outcome risk

Methods

MB

rbias

SE

SD(rBias)

rMSE

Coverage

CoverageT

Significance

N used

Exposure prevalence = 10.55% (observed)

      

1%

Crude

0.5542

-66.85

0.470

49.37

0.831

78.0

17.2

17.2

4000

FSF−equ

0.0811

-25.04

0.498

51.46

0.572

96.0

41.0

41.8

3971

FSX−equ

0.0760

-26.00

0.500

52.11

0.582

96.2

38.8

39.6

3812

FSF−unequ

0.1146

-25.04

0.498

51.46

0.572

96.0

41.0

41.8

3971

FSX−unequ

0.1098

-26.00

0.500

52.11

0.582

96.2

38.8

39.6

3812

OWF

0.0006

-7.69

0.483

47.79

0.484

97.0

52.4

54.8

4000

OWX

0.0001

-8.08

0.486

48.45

0.491

97.2

51.6

54.0

3835

10%

Crude

0.5524

-70.06

0.136

14.49

0.715

0.0

0.0

59.6

4000

FSF−equ

0.0810

-47.74

0.146

12.95

0.495

5.2

5.2

94.0

3970

FSX−equ

0.0761

-47.92

0.147

13.08

0.497

5.0

5.0

93.8

3815

FSF−unequ

0.1145

-47.74

0.146

12.95

0.495

5.2

5.2

94.0

3970

FSX−unequ

0.1100

-47.92

0.147

13.08

0.497

5.0

5.0

93.8

3815

OWF

0.0006

-39.30

0.140

12.30

0.412

14.4

14.4

99.6

4000

OWX

0.0001

-39.52

0.141

12.28

0.414

14.6

14.6

99.6

3839

30%

Crude

0.5526

-72.39

0.067

6.91

0.727

0.0

0.0

96.8

4000

FSF−equ

0.0803

-61.44

0.071

6.18

0.617

0.0

0.0

100.0

3968

FSX−equ

0.0759

-61.47

0.071

6.19

0.618

0.0

0.0

100.0

3814

FSF−unequ

0.1135

-61.44

0.071

6.18

0.617

0.0

0.0

100.0

3968

FSX−unequ

0.1096

-61.47

0.071

6.19

0.618

0.0

0.0

100.0

3814

OWF

0.0006

-56.17

0.069

6.05

0.565

0.0

0.0

100.0

4000

OWX

0.0001

-56.20

0.070

6.10

0.565

0.0

0.0

100.0

3840

Exposure prevalence = 2.5%

       

1%

Crude

0.643

-564.17

0.815

959.38

11.17

76.4

10.0

33.6

4000

FSF−equ

0.196

-689.45

0.849

1173.21

13.64

72.2

17.2

44.4

3859

FSX−equ

0.188

-663.38

0.863

1157.41

13.36

72.4

15.4

41.8

3360

FSF−unequ

0.291

-596.65

0.849

1005.94

11.69

72.2

17.2

44.4

3859

FSX−unequ

0.293

-575.08

0.863

996.42

11.50

72.4

15.4

41.8

3360

OWF

0.031

-606.14

0.825

1129.22

12.82

74.8

24.0

49.2

4000

OWX

0.116

-614.94

0.836

1132.19

12.89

74.6

23.4

48.8

3459

10%

Crude

0.645

-73.23

0.270

27.75

0.78

13.2

13.2

24.8

4000

FSF−equ

0.196

-48.49

0.319

30.44

0.57

76.0

42.4

42.6

3857

FSX−equ

0.188

-48.96

0.323

31.65

0.58

76.0

42.0

42.2

3339

FSF−unequ

0.291

-48.49

0.319

30.44

0.57

76.0

42.4

42.6

3857

FSX−unequ

0.294

-48.96

0.323

31.65

0.58

76.0

42.0

42.2

3339

OWF

0.006

-40.89

0.273

22.97

0.47

78.4

61.0

63.4

4000

OWX

0.123

-42.62

0.277

35.88

0.56

77.6

59.6

61.6

3443

30%

Crude

0.645

-73.25

0.131

12.57

0.74

0.0

0.0

56.2

4000

FSF−equ

0.191

-61.63

0.154

14.17

0.63

0.0

0.0

70.8

3860

FSX−equ

0.186

-60.66

0.155

13.79

0.62

0.2

0.2

72.4

3355

FSF−unequ

0.281

-61.63

0.154

14.17

0.63

0.0

0.0

70.8

3860

FSX−unequ

0.287

-60.66

0.155

13.79

0.62

0.2

0.2

72.4

3355

OWF

0.030

-56.15

0.132

11.02

0.57

0.0

0.0

90.8

4000

OWX

0.031

-56.21

0.133

11.06

0.57

0.2

0.2

90.6

3454

  1. Footnotes:
  2. 1. Crude = summarized by raw data without any balancing method; OW = overlap weighting method; FS = propensity score based fine stratification method
  3. 2. ‘F’ = a full set of data; ‘X’ = a subset of data after removing those unmatched
  4. 3. ‘equ’ = ATE with the equal weighting between groups; ‘unequ’ = ATE with the unequal weighting, where total weight in one group equivalent to the sample size in that group
  5. 4. The best values are bolded and can be used to guide which method performs the best per evaluation criterion
  6. 5. MB = Mahalanobis balance; rBias = relative bias = 100*(estimated effect – true effect) /true effect; SE = average estimated standard error; SD(rBias) = empirical standard deviation of relative bias x 100; rMSE = square root of mean squared error that combines squared bias (not relative bias) and its variance; Coverage = proportion of samples whose 95% CI cover the true effect; CoverageT = proportion of samples whose 95% CI cover the true effect but not zero; Significance = proportion of samples obtaining a significant effect (by a weighted GLM with a two-sided p-value < 0.05); N used = average total sample size that was used further for GLM.