Table 5 The curve of receiver operating characteristic (ROC) of the studied indices for optimum cutoff points in diagnosing sickle cell disease and trait (compared to healthy control)

 RDWI

> 273.91

0.807

(0.697, 0.891)

68.18

100

100

87.7

68.18

< 0.001*

 ML_I

> 18.98

0.709

(0.590, 0.810)

59.09

90

72.2

83.3

49.09

0.011*

 GK

> 88.2

0.798

(0.687, 0.884)

75.29

100

100

89.3

72.73

0.002*

 EF

> 24.5

0.780

(0.666, 0.869)

63.64

98

93.3

86

61.64

0.002*

 SL

≤ 1639.2

0.815

(0.705, 0.896)

59.09

100

100

84.7

59.09

< 0.001*

 SI

> 6.36

0.733

(0.615, 0.830)

63.64

96

87.5

85.7

59.64

0.007*

 RI

> 3.04

0.925

(0.839, 0.974)

77.27

100

100

90.9

77.27

< 0.001*

 EI

> 45

0.613

(0.491, 0.725)

40.91

94

75

78.3

34.91

0.191

 Sir_I

> 44.2

0.646

(0.524, 0.755)

59.09

88

68.4

83

47.09

0.098

 HH

> 22.09

0.919

(0.830, 0.970)

90.91

92

83.3

95.8

82.91

< 0.001*

 RDWI

> 273.91

0.549

(0.432, 0.662)

28.57

100

100

71.4

28.57

0.508

 ML_I

≤ 19.13

0.517

(0.401, 0.632)

75

6

30.9

30

19

0.824

 GK

≤ 56.91

0.617

(0.500, 0.725)

46.43

98

92.9

76.6

44.43

0.164

 EF

≤ 0.9

0.6

(0.483, 0.710)

46.43

98

92.9

76.6

44.43

0.232

 SL

≤ 1785.6

0.881

(0.788, 0.944)

78.57

92

84.6

88.5

70.57

< 0.001*

 SI

> 5.66

0.548

(0.431, 0.661)

50

78

56

73.6

28

0.544

 RI

> 3.04

0.770

(0.661, 0.858)

46.43

100

100

76.9

46.43

< 0.001*

 EI

≤ 21.1

0.591

(0.474, 0.701)

35.71

94

76.9

72.3

29.71

0.226

 Sir_I

≤ 30.9

0.643

(0.527, 0.749)

53.57

94

83.3

78.3

47.57

0.086

 HH

> 22.52

0.668

(0.552, 0.770)

35.71

100

100

73.5

35.71

0.016*