|
Cutoff points
|
N (%)
|
Sensitivity (CI 95%) %
|
Specificity (CI 95%) %
|
PPV %
|
NPV %
|
Accuracy %
|
Youden’s index (*)
|
|---|
|
≥ 1
|
363 (81.2)
|
100.0 (91.2 – 100.0)
|
20.6 (16.8 – 24.9)
|
11.0 (8.0 – 14.7)
|
100.0 (95.7 – 100.0)
|
60.3 (58.4 – 62.3)
|
0.206
|
|
≥ 2
|
303 (67.8)
|
97.5 (86.8 – 99.9)
|
35.1 (30.5 – 40.0)
|
12.9 (9.3 – 17.2)
|
99.3 (96.2 – 100.0)
|
66.3 (62.9 – 70.0)
|
0.326
|
|
≥ 3
|
239 (53.5)
|
95.0 (83.1 – 99.4)
|
50.6 (45.6 – 55.6)
|
15.9 (11.5 – 21.2)
|
99.0 (96.6 – 99.9)
|
72.8 (68.6 – 77.0)
|
0.456
|
|
≥ 4
|
196 (43.8)
|
90.0 (76.3 – 97.2)
|
60.7 (55.8 – 65.5)
|
18.4 (13.2 – 24.5)
|
98.4 (96.0 – 99.6)
|
75.3 (70.1 – 80.6)
|
0.507
|
|
≥ 5
|
150 (33.6)
|
82.5 (67.2 – 92.7)
|
71.3 (66.6 – 75.6)
|
22.0 (15.7 – 29.5)
|
97.6 (95.2 – 99.0)
|
76.9 (70.5 – 83.2)
|
0.538
|
|
≥ 6
|
122 (27.3)
|
82.5 (67.2 – 92.7)
|
78.1 (73.8 – 82.1)
|
27.0 (19.4 – 35.8)
|
97.8 (95.6 – 99.1)
|
80.3 (74.0 – 86.6)
|
0.606
|
|
≥ 7
|
102 (22.8)
|
82.5 (67.2 – 92.7)
|
83.0 (79.0 – 86.6)
|
32.4 (23.4 – 42.3)
|
98.0 (95.9 – 99.2)
|
82.8 (76.5 – 89.0)
|
0.655
|
|
≥ 8
|
85 (19.0)
|
80.0 (64.4 – 90.9)
|
87.0 (83.3 – 90.1)
|
37.6 (27.4 – 48.8)
|
97.8 (95.7 – 99.0)
|
83.5 (77.0 – 90.0)
|
0.670
|
|
≥ 9
|
67 (15.0)
|
72.5 (56.1 – 85.4)
|
90.7 (87.4 – 93.3)
|
43.3 (31.2 – 56.0)
|
97.1 (94.9 – 98.5)
|
81.6 (74.4 – 88.7)
|
0.632
|
|
≥10
|
61 (13.6)
|
70.0 (53.5 – 83.4)
|
91.9 (88.8 – 94.4)
|
45.9 (33.1 – 59.2)
|
96.9 (94.6 – 98.4)
|
80.9 (73.6 – 88.3)
|
0.619
|
|
≥ 11
|
53 (11.9)
|
65.0 (48.3 – 79.4)
|
93.4 (90.5 – 95.6)
|
49.1 (35.1 – 63.2)
|
96.4 (94.1 – 98.0)
|
79.2 (71.6 – 86.8)
|
0.584
|
|
≥ 12
|
43 (9.6)
|
55.0 (38.5 – 70.7)
|
94.8 (92.2 – 96.8)
|
51.2 (35.5 – 66.7)
|
99.5 (93.0 – 97.3)
|
74.9 (67.0 – 82.8)
|
0.498
|
|
≥ 13
|
33 (7.4)
|
47.5 (31.5 – 63.9)
|
96.6 (94.3 – 98.1)
|
57.6 (39.2 – 74.5)
|
94.9 (92.4 – 96.8)
|
72.0 (64.1 – 79.9)
|
0.441
|
|
≥ 14
|
29 (6.5)
|
45.0 (29.3 – 61.5)
|
97.3 (95.2 – 98.6)
|
62.1 (42.3 – 79.3)
|
94.7 (92.1 – 96.7)
|
71.1 (63.3 – 79.0)
|
0.423
|
|
≥ 15
|
23 (5.1)
|
35.0 (20.6 – 51.7)
|
97.8 (95.8 – 99.0)
|
60.9 (38.5 – 80.3)
|
93.9 (91.1 – 96.0)
|
66.4 (58.9 – 73.9)
|
0.328
|
|
≥ 16
|
18 (4.0)
|
25.0 (12.7 – 41.2)
|
98.0 (96.2 – 99.1)
|
55.6 (30.8 – 78.5)
|
93.0 (90.2 – 95.2)
|
61.5 (54.7 – 68.3)
|
0.230
|
|
≥ 17
|
15 (3.4)
|
22.5 (10.8 – 38.5)
|
98.5 (96.8 – 99.5)
|
60.0 (32.3 – 83.7)
|
92.8 (90.0 – 95.1)
|
60.5 (53.9 – 67.1)
|
0.210
|
|
≥ 18
|
12 (2.7)
|
20.0 (9.1 – 35.6)
|
99.0 (97.5 – 99.7)
|
66.7 (34.9 – 90.1)
|
92.6 (89.8 – 94.9)
|
59.5 (53.2 – 65.8)
|
0.190
|
|
≥ 19
|
10 (2.2)
|
17.5 (7.3 – 32.8)
|
99.3 (97.9 – 99.8)
|
70.0 (34.8 – 93.3)
|
92.4 (89.6 – 94.7)
|
58.4 (52.4 – 64.4)
|
0.168
|
|
≥ 20
|
10 (2.2)
|
17.5 (7.3 – 32.8)
|
99.3 (97.9 – 99.8)
|
70.0 (34.8 – 93.3)
|
92.4 (89.6 – 94.7)
|
58.4 (52.4 – 64.4)
|
0.168
|
|
≥ 21
|
7 (1.6)
|
12.5 (4.2 – 26.8)
|
99.5 (98.2 – 99.9)
|
71.4 (29.0 – 96.3)
|
92.0 (89.1 – 94.4)
|
56.0 (50.8 – 61.2)
|
0.120
|
|
≥ 22
|
6 (1.3)
|
12.5 (4.2 – 26.8)
|
99.8 (98.6 – 100)
|
83.3 (35.9 – 99.6)
|
92.1 (89.1 – 94.4)
|
56.1 (50.9 – 61.3)
|
0.123
|
|
≥ 23
|
4 (0.9)
|
10.0 (2.8 – 23.7)
|
100.0 (99.1 – 100.0)
|
100.0 (39.8 – 100.0)
|
91.9 (88.9 - 94.2)
|
55.0 (50.3 - 59.7)
|
0.100
|
- Note: PPV = positive predictive value; NPV = negative predictive value.
- (*) Youden’s índex = [sensitivity + specificity - 1].
