Table 7.

Odds Ratio for IPF versus Alternative Diagnoses Shown in Columns for Each Unit Increase in Index Score (Derivation and Validation IPF Cohorts)

		Adjusted*			Unadjusted
		Healthy Control Subjects	a-ILD	RA-ILD	Healthy Control Subjects	a-ILD	RA-ILD
Derivation IPF
OR		1.9	1.9	1.0	2.7	2.1	1.1
95% CI		1.1–3.3	1.2–2.8	0.6–1.5	2.0–3.6	1.4–3.0	0.7–1.6
P value		0.015	0.005	0.82	<0.0001	0.0001	0.65
Validation IPF
OR		2.7	2.3	0.8	3.2	2.5	1.0
95% CI		1.5–4.7	1.3–3.9	0.5–1.5	2.2–4.6	1.6–4.0	0.6–1.8
P value		0.0009	0.004	0.56	<0.0001	0.0001	0.89

Definition of abbreviations: a-ILD = alternative interstitial lung disease; CI = confidence interval; IPF = idiopathic pulmonary fibrosis; OR = odds ratio comparing 0 to 3 point index score delineations in each row; RA-ILD = rheumatoid arthritis–associated interstitial lung disease.

^*Adjustment variables include sex, age, smoking status, and FVC (% predicted).