Table 5.

Positive predictive value of the modified idiopathic pulmonary fibrosis algorithm for identifying cases with an interstitial lung disease expert diagnosis of idiopathic pulmonary fibrosis, with sensitivity analyses for alternative case classification methods

Case Definition	PPV of Modified IPF Algorithm (95% CI)
	Sample 1 (n = 71)	Sample 2 (n = 70)
Primary analysis
Adjudicated diagnosis of IPF	70.4 (49.8–86.2)	61.8 (43.6–77.8)
Sensitivity analyses
Adjudicated diagnosis of IPF or unclassifiable	85.2 (66.3–95.8)	85.3 (68.9–95.0)
Treating clinician chart diagnosis	77.8 (57.7–91.4)	61.8 (43.6–77.8)
Any ILD based on expert CT image review	88.9 (70.8–97.6)	100 (89.7–100)

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