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Table 1 Results of the Monte Carlo simulations

From: Optimum binary cut-off threshold of a diagnostic test: comparison of different methods using Monte Carlo technique

 

N

 

Mutual information

Youden

Likelihood ratio

  

Mean

SD

Mean

Sd

Mean

SD

Scenario 1 (lognormal)

50

Cut-off

8.1 - 10.4

1.7 - 2.6

9.0 - 9.7

1.2 - 1.8

9.9 - 10.1

0.5 - 1.1

Se

0.78 - 0.86

0.17 - 0.30

0.82 - 0.91

0.10 - 0.14

0.74 - 0.76

0.08 - 0.16

Sp

0.69 - 0.76

0.18 - 0.23

0.73 - 0.82

0.12 - 0.17

0.78 - 0.78

0.06 - 0.14

100

Cut-off

8.1 - 10.0

1.4 - 2.2

9.2 - 9.5

1.0 - 1.4

10.0 - 10.10

0.4 - 0.7

Se

0.84 - 0.89

0.11 - 0.19

0.81 - 0.87

0.09 - 0.13

0.74 -0.75

0.05 - 0.11

Sp

0.65 - 0.74

0.15 - 0.22

0.72 - 0.78

0.09 - 0.15

0.78 - 0.78

0.04 - 0.10

200

Cut-off

7.8 - 9.7

1.1 - 1.9

9.2 - 9.4

0.8 - 1.1

10.0 - 10.1

0.3 - 0.5

Se

0.83 - 0.91

0.08 - 0.16

0.82 - 0.85

0.07 - 0.10

0.74 - 0.74

0.04 - 0.08

Sp

0.61 - 0.72

0.12 - 0.18

0.71 - 0.75

0.08 - 0.12

0.78 - 0.78

0.03 - 0.07

Scenario 2 (chi-square)

50

Cut-off

7.4 - 9.3

3.3 - 4.1

7.5 - 8.1

1.9 - 2.7

8.2 - 8.4

0.6 - 1.1

Se

0.67 - 0.70

0.26 - 0.35

0.69 - 0.80

0.17 - 90.21

0.59 - 0.61

0.08 - 0.17

Sp

0.62 - 0.73

0.24 - 0.30

0.65 - 0.77

0.17 - 0.22

0.69 - 0.70

0.07 - 0.15

100

Cut-off

7.4 - 9.0

3.1 - 4.1

7.5 - 8.0

1.5 - 2.2

8.3 - 8.4

0.4 - 0.8

Se

0.66 - 0.71

0.23 - 0.30

0.68 - 0.76

0.14 - 0.18

0.59 - 0.61

0.06 - 0.12

Sp

0.61 - 0.69

0.23 - 0.29

0.64 - 0.72

0.14 - 0.19

0.69 - 0.70

0.05 - 0.10

200

Cut-off

7.0 - 8.8

2.4 - 3.9

7.5 - 7.9

1.2 - 1.8

8.3 - 8.4

0.3 - 0.5

Se

0.67 - 0.72

0.20 - 0.27

0.67 - 0.72

0.12 - 0.16

0.59 - 0.60

0.04 - 0.09

Sp

0.59 - 0.65

0.21 - 0.26

0.63 - 0.67

0.12 - 0.17

0.69 - 0.70

0.03 - 0.07

Scenario 3 (inverse gamma)

50

Cut-off

5.1 - 7.1

1.7 - 2.6

5.1 - 5.8

0.9 - 1.6

5.4 - 5.8

0.5 - 0.9

Se

0.64 - 0.76

0.17 - 0.34

0.75 - 0.83

0.11 - 0.17

0.69 - 0.72

0.08 - 0.17

Sp

0.80 - 0.87

0.15 - 0.20

0.81 - 0.90

0.11 - 0.15

0.84 - 0.85

0.05 - 0.12

100

Cut-off

5.1 - 7.2

1.4 - 2.3

5.1 - 5.6

0.8 - 1.3

5.4 - 5.7

0.3 - 0.6

Se

0.63 - 0.76

0.15 - 0.27

0.75 - 0.79

0.09 - 0.14

0.69 - 0.71

0.06 - 0.12

Sp

0.81 - 0.87

0.12 - 0.19

0.81 - 0.85

0.09 - 0.13

0.84 - 0.85

0.04 - 0.08

200

Cut-off

5.1 - 7.2

1.1 - 2.2

5.1 - 5.3

0.6 - 1.0

5.5 - 5.6

0.2 - 0.5

Se

0.62 - 0.76

0.12 - 0.21

0.75 - 0.78

0.08 - 0.11

0.69 - 0.71

0.04 - 0.09

Sp

0.80 - 0.89

0.09 - 0.17

0.80 - 0.83

0.08 - 0.11

0.84 - 0.85

0.02 - 0.06

Scenario 4 (mixed)

50

Cut-off

9.9 - 14.2

1.6 - 2.5

10.4 - 14.1

1.6 - 2.9

12.1 - 14.6

1.1 - 1.8

Se

0.41 - 0.47

0.32 - 0.45

0.99 - 1.00

0.01 - 0.03

0.98 - 1.00

0.02 - 0.03

Sp

0.65 - 0.82

0.22 - 0.24

0.97 - 0.99

0.03 - 0.04

0.97 - 0.98

0.03 - 0.06

100

Cut-off

11.0 - 14.6

1.3 - 2.0

11.7 - 14.2

1.2 - 2.3

12.6 - 13.9

0.7 - 1.6

Se

0.48 - 0.69

0.43 - 0.47

0.98 - 1.00

0.02 - 0.02

0.98 - 0.99

0.02 - 0.03

Sp

0.79 - 0.94

0.13 - 0.23

0.97 - 0.98

0.02 - 0.04

0.97 - 0.97

0.02 - 0.05

200

Cut-off

11.4 - 14.6

1.0 - 1.4

12.5 - 13.9

0.9 - 1.7

13.1 - 13.6

0.5 - 1.2

Se

0.65 - 0.91

0.26 - 0.46

0.98 - 0.99

0.01 - 0.02

0.98 - 0.98

0.01 - 0.02

Sp

0.90 - 0.97

0.04 - 0.16

0.96 - 0.98

0.02 - 0.03

0.96 - 0.97

0.01 - 0.03

  1. For the 4 distributional scenarios and for total numbers of 50, 100 and 200 fictitious "individuals", the ranges of mean values and SD values, found by varying P(D) from 0.1 to 0.9 in steps of 0.1, of optimal cut-off limits and sensitivities and specificities are reported. Mean values and SD values are based on 1000 repetitions each.