Table 3

Results of ROC curve analysis and contingency table analysis for NT-proBNP and PFT

Variable

Comparison

groups

Optimal cut point

Sensitivity

(95% CI)

Specificity

(95% CI)

+LR

-LR

AUC

NT-proBNP

(ng/ml)

PAH versus control

≥ 209.8

92.9%

(64.1%-99.6%)

100%

(85.9%-99.7%)

-

0.07

(0.01-0.47)

0.93

(0.80-1.0)

PAH versus ILD

≥ 360.5

85.7%

(56.2%-97.0%)

100.0%

(71.8%-99.5%)

-

0.14

(0.04-0.52)

0.92

(0.78-1.0)

DLCO_corr%

PAH versus control

< 70.3

100%

(73.2%-99.3%)^a

100%

(85.7%-99.7%)^a

-

-

1.0

PAH versus ILD

Nil

-

-

-

-

0.42

(0.22-0.63)

FVC/DLCO

PAH versus control

≥ 1.66

64.3%

(35.6%-86.0%)

96.7%

(80.9%-99.8%)

19.3

(2.7- .)

0.37

(0.18-0.75)

0.90

(0.78-1.0)

PAH versus ILD

≥ 1.82

50.0%

(24.0%-76.0%)

94.4%

(70.6%-99.7%)

9.0

(1.2-64.9)

0.53

(0.31-0.90)

0.71

(0.51-0.90)

DLCO < 70.3%

and

FVC/DLCO

≥ 1.82

PAH versus control

-

50.0%

(24.0%-76.0%)

100%

(85.9%-99.7%)

-

0.63

(0.43-0.91)

-

PAH versus ILD

-

50.0%

(24.0%-76.0%)

94.4%

(70.6%-99.7%)

6.75

(0.9-50.2)

0.66

(0.45-0.98)

-

DLCO < 70.3% and

FVC/DLCO ≥ 1.82 (A)

and/or

NT-proBNP ≥ 209.8 (B)

PAH versus control

-

100%

(73.2%-99.3%)^a

100%

(85.9%-99.7%)^a

-

-

-

PAH versus ILD

-

100%

(73.2%-99.3%)^a

77.8%

(51.9%-92.6%)

4.50

(1.90-10.7)

-

-

DLCO, diffusing capacity of lungs for carbon monoxide, % predicted; FVC, forced vital capacity, % predicted; ILD, interstitial lung disease; NT-proBNP, N-terminal pro brain natriuretic peptide; PAH, pulmonary arterial hypertension; (A) and (B) refer to the two components of the "composite" screening model. ^aBecause of the relatively small sample size, the upper limit of the 95% CI approximates but does not equal 100%.

Thakkar et al. Arthritis Research & Therapy 2012 14:R143   doi:10.1186/ar3876