Table 3.

Summary of multivariate analysis for the outcome measurement of DLCO_adj (% predicted). Among all the input variables listed in Table 2, the leading three variables by their independent contributions to the variance in DLCO_adj were the alveolar volume (% predicted), the blood vessel volume fraction and the parenchymal radiodensity. The statistical significances of their associations with DLCO_adj after adjusting for potential confounders were provided by the results of the multiple linear regression model. The tri-variate model of DLCO_adj (% predicted) combines the leading three input variables. Definition of abbreviations: VA (% pred.)—alveolar volume, % of predicted reference; Blood vessel V.F.—blood vessel volume fraction; PDm—mode of parenchymal radiodensity histogram measured by CT.

	VA (% Pred.)	Blood Vessel V.F.	PDm	Days Since Symptom Onset	All Other Input Variables	Tri-Variate Model
Independent contribution to the variance of DLCO_adj (% pred.), n = 45	27%	10%	12.3%	2.6%	<2%	49.4%
Multiple linear regression model beta coefficient and p value, n = 45	β = 0.66, p = 0.031	β = 186, p = 0.005	β = 0.27, p = 0.018	β = −0.03, p = 0.17	p > 0.25	p < 0.001