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Table 2 Evaluation parameters in three different strategies

From: Role of a new age-adjusted D-dimer cutoff value for preoperative deep venous thrombosis exclusion in elderly patients with hip fractures

 

Negative number n (%)

Number needed to test

False negatives number (%)

Positive predictive value (%, 95% CI)

Negative predictive value (%, 95% CI)

Sensitivity (%, 95% CI)

Specificity (%, 95% CI)

0.5

594 (22)

4.2

42 (15)

11 (9.7, 12.4)

93 (90.5, 94.8)

85 (80.1, 88.9)

22 (20.7, 24.0)

0.01*age

979 (35)

2.5

64 (23)

12 (10.7, 13.8)

94 (91.7, 94.9)

77 (71.7, 81.8)

37 (35.0, 38.8)

0.02*age

1293 (59)

1.5

115 (41)

15 (12.7, 16.9)

93 (91.6, 94.1)

59 (52.9, 64.7)

61 (59.3, 63.2)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

148 (30)

3

8 (15)

14 (10.2, 17.7)

95 (89.3, 97.5)

86 (72.8, 93.1)

32 (27.5, 36.4)

0.01*age

183 (37)

2.4

10 (18)

14 (10.8, 18.9)

95 (89.9, 97.2)

82 (68.6, 90.5)

39 (34.8, 44.1)

0.02*age

291 (59)

1.5

26 (42)

14 (9.9, 19.9)

91 (87.0, 94.0)

53 (38.9, 66.1)

60 (55.5, 64.8)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

166 (32)

2.8

17 (38)

8 (5.4, 11.4)

90 (83.9, 93.7)

62 (46.5, 75.8)

32 (27.4, 35.9)

0.01*age

221 (43)

2.1

19 (42)

9 (5.9, 12.7)

91 (86.7, 94.6)

58 (42.2, 72.0)

43 (38.2, 47.3)

0.02*age

335 (65)

1.4

26 (58)

10 (6.5, 16.0)

92 (88.7, 94.8)

42 (28.0, 57.8)

65 (60.8, 69.6)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

121 (22)

4

13 (19)

13 (10.2, 16.8)

89 (82.0, 93.9)

81 (70.0, 89.4)

22 (18.7, 26.3)

0.01*age

208 (37)

2.3

22 (31)

13 (10.5, 18.0)

89 (84.2, 93.1)

69 (56.2, 78.9)

38 (34.0, 42.9)

0.02*age

340 (61)

1.4

36 (51)

16 (11.3, 21.5)

89 (85.5, 92.4)

49 (36.6, 60.7)

63 (58.2, 67.0)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

97 (16)

5.7

2 (4)

10 (7.4, 12.5)

94 (82.8, 98.5)

95 (84.5, 98.)

9 (6.5, 11.4)

0.01*age

189 (31)

2.9

7 (12)

11 (8.1, 14.8)

93 (89.2, 96.0)

72 (58.3, 82.6)

40 (36.3, 44.7)

0.02*age

332 (54)

1.7

14 (24.56)

15 (11.5, 20.3)

96 (92.9, 97.6)

75 (62.0, 85.5)

57 (53.2, 61.5)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

44 (11)

8.4

2 (5.26)

10 (7.1, 13.6)

96 (83.3, 99.2)

95 (80.9, 99.1)

11 (8.4, 15.2)

0.01*age

120 (29)

3.1

6 (15.79)

11 (7.9, 15.5)

95 (89.0, 98.0)

84 (68.1, 93.4)

31 (26.3, 35.9)

0.02*age

240 (59)

1.5

13 (34.21)

15 (10.1, 21.5)

95 (90.7, 97.0)

66 (48.6, 79.9)

62 (56.3, 66.5)

P

–

–

–

–

–

< 0.05

< 0.05

0.5

18 (10)

8.8

0 (0.00)

10 (5.7, 15.7)

100 (78.1, 100.0)

100 (74.7, 100.0)

11 (7.1, 17.7)

0.01*age

58 (34)

2.7

(0.00)

13 (7.7, 20.9)

100 (92.3, 100.0)

100 (74.7, 100.0)

37 (29.3, 44.8)

0.02*age

96 (55)

1.6

0 (0.00)

20 (11.7, 30.4)

100 (95.2, 100.0)

100 (74.7, 100.0)

61 (52.7, 68.3)

P

–

–

–

–

–

> 0.05

< 0.05

  1. Number needed to test to find one normal D-dimer test result
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Journal of Orthopaedic Surgery and Research

ISSN: 1749-799X