Table 3 Performance measures of screening tools according to RDI thresholds.

From: The No-Apnea score for early obstructive sleep apnea detection in a sleep clinic: a study of diagnostic accuracy and comparative performance of three screening instruments

Index test

Sensitivity (%)

Specificity (%)

Acc (%)

F1 score (%)

PPV (%)

NPV (%)

LR + 

LR -

AUC

OR

RDI ≥ 5

 No-Apnea

96.9

(96.0, 97.6)

27.6

(21.4, 34.4)

90.37

94.8

92.8

(91.6, 93.9)

47.8

(38.3, 57.4)

1.34

(1.23, 1.46)

0.22

(0.12, 0.35)

0.622

(0.59, 0.65)

11.80

(7.88, 17.70)

 STOP-BANG

83.5

(81.7, 85.1)

53.6

(46.3, 60.7)

80.69

88.7

94.6

(93.4, 95.6)

25.2

(21.1, 29.6)

1.8

(1.55, 2.09)

0.31

(0.26, 0.36)

0.685

(0.64, 0.72)

5.84

(4.30, 7.92)

 NoSAS

47.3

(45.1, 49.6)

87.8

(82.3, 92.0)

51.12

63.7

97.4

(96.1, 98.3)

14.7

(12.7, 16.9)

3.87

(2.65, 5.64)

0.60

(0.56, 0.64)

0.675

(0.65, 0.70)

6.44

(4.18, 9.93)

RDI ≥ 15

 No-Apnea

98.3

(97.5, 98.9)

14.9

(12.1, 18.0)

74.75

84.8

74.6

(72.6, 76.5)

77.9

(69.1, 85.1)

1.16

(1.12, 1.20)

0.11

(0.07, 0.17)

0.566

(0.55, 0.58)

10.30

(6.57, 16.20)

 STOP-BANG

87.5

(85.7, 89.1)

39.0

(35.0, 43.1)

73.79

82.7

78.4

(76.4, 80.4)

55.2

(50.2, 60.0)

1.43

(1.34, 1.53)

0.32

(0.27, 0.37)

0.633

(0.61, 0.65)

4.48

(3.57, 5.61)

 NoSAS

54.0

(51.4, 56.5)

81.2

(77.8, 84.3)

61.67

66.9

87.9

(85.6, 90.0)

41.0

(38.2, 43.9)

2.87

(2.41, 3.41)

0.56

(0.53, 0.61)

0.675

(0.65, 0.69)

5.06

(4.02, 6.37)

RDI ≥ 30

 No-Apnea

99.0

(98.2, 99.5)

9.6

(7.9, 11.5)

52.90

67.1

50.7

(48.5, 52.9)

91.2

(84.3, 95.7)

1.09

(1.07, 1.12)

0.10

(0.05, 0.19)

0.543

(0.53, 0.55)

10.60

(5.56, 20.20)

 STOP-BANG

91.1

(89.2, 92.8)

30.4

(27.7, 33.2)

59.80

68.7

55.1

(52.7, 57.6)

78.4

(74.2, 82.3)

1.31

(1.25, 1.37)

0.29

(0.23, 0.36)

0.607

(0.59, 0.62)

4.47

(3.47, 5.75)

 NoSAS

61.3

(58.2, 64.3)

72.2

(69.4, 74.9)

66.94

64.2

67.5

(64.3, 70.5)

66.5

(63.7, 69.2)

2.21

(1.98, 2.46)

0.53

(0.49, 0.58)

0.668

(0.64, 0.68)

4.12

(3.43, 4.95)

  1. Data in parentheses are 95% confidence intervals. We employed the No-Apnea, STOP-Bang, and NoSAS tests as index measures. The reference standard was the RDI derived from PSG. Positive outcome thresholds for the No-Apnea, STOP-Bang, and NoSAS tests were established at scores of ≥ 3, ≥ 3, and ≥ 8, respectively. RDI < 5 indicates a person without OSA. RDI levels of ≥ 5, ≥ 15, and ≥ 30 correspond to individuals with OSA of any severity, those with moderate to severe OSA, and those specifically with severe OSA, respectively.
  2. Acc, accuracy; AUC, area under the ROC curve; LR+, positive likelihood ratio; LR−, negative likelihood ratio; NoSAS, neck, obesity, snoring, age, sex; NPV, negative predictive value; OR, odds ratio; PPV, positive predictive value; RDI, respiratory disturbance index; ROC, receiver operating characteristics; STOP-Bang, snoring, tiredness, observed apnea, blood pressure.
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