Table 2

Changes from pretest probability of weaning success to post-test probability for different likelihood ratios obtained in several studies that evaluated the f/VT ratio

Post-test probability of weaning success (%)

Likelihood ratio of a positive test result^*

Likelihood ratio of a negative test result^†

Pretest probability of weaning success (%)

1.45

1.51

2.69

2.74

0.05

0.09

0.27

0.36

30

38

39

53

54

2

4

10

13

40

49

50

64

65

3

6

15

19

50

59

60

73

73

5

8

21

26

60

68

69

80

80

7

12

29

35

70

70

77

86

86

10

17

39

46

80

85

86

91

92

17

26

52

59

^*Positive test result is a value of rapid shallowbreathing index (f/VT) lower than 105 or 100; ^†negative testresult is a value of f/VT higher than 105 or 100.

Alía and Esteban Critical Care 2000 4:72   doi:10.1186/cc660