Table 3.

Positive predictive value of the idiopathic pulmonary fibrosis algorithm for identifying cases with an adjudicated diagnosis of idiopathic pulmonary fibrosis, with sensitivity analyses for alternative case classification methods

Case Definition	PPV of IPF Algorithm (95% CI)
	Sample 1 (n = 71)	Sample 2 (n = 70)
Primary analysis
Adjudicated diagnosis of IPF	42.2 (30.6–54.6)	48.6 (36.4–60.8)
Sensitivity analyses
Adjudicated diagnosis of IPF or unclassifiable	57.7 (45.4–69.4)	65.7 (53.4–76.7)
Treating clinician chart diagnosis	49.3 (37.2–61.4)	47.1 (35.0–59.4)
Any ILD based on expert CT image review	76.1 (64.4–85.4)	85.7 (75.3–92.9)

Definition of abbreviations: CI = confidence interval; CT = computed tomographic; ILD = interstitial lung disease; IPF = idiopathic pulmonary fibrosis; PPV = positive predictive value.