Table 2.

Results of multivariate logistic regression analysis with selected variables as explanatory variables (upper) and after stepwise variable selection (lower).

Variables	Partial regression coefficient	95% CI of partial regression coefficient	Odds ratio	95% CI of Odds ratio	P value
Age	− 0.0372	− 0.1150 to 0.0407	0.9635	0.8914 to 1.0415	0.3491
Diffuse HRCT pattern	1.3448	0.1306 to 2.5590	3.8373	1.1395 to 12.9224	0.0299*
KL-6	− 0.0007	− 0.0014 to 0.0001	0.9993	0.9986 to 0.9999	0.0353*
SP-D	0.0009	− 0.0007 to 0.0026	1.0009	0.9993 to 1.0026	0.2711
LDH	0.0045	− 0.0023 to 0.0114	1.0045	0.9977 to 1.0114	0.1972
CRP	0.0863	0.0082 to 0.1643	1.0901	1.0082 to 1.1786	0.0303*
PaO2/FiO2 ratio	− 0.0110	− 0.0186 to 0.0035	0.9890	0.9816 to 0.9965	0.0041*
Antifibrotic agents use	− 1.2087	− 2.5842	0.1669	0.0755 to 1.1817	0.0851

Variables	Partial regression coefficient	95% CI of partial regression coefficient	Odds ratio	95% CI of odds ratio	P value
Stepwise variable selection
Diffuse HRCT pattern	1.3386	0.2430 to 2.4342	3.8137	1.2751 to 11.4065	0.0166*
CRP	0.0943	0.0217 to 0.1669	1.0989	1.0219 to 1.1817	0.0109*
PaO2/FiO2 ratio	− 0.0082	− 0.0142 to 0.0022	0.9919	0.9859 to 0.9978	0.0074**

CI, confidence interval; HRCT, high-resolution computed tomography; KL-6, Krebs von der Lungen-6; SP-D, surfactant protein D; SP-A, surfactant protein A; LDH, lactate dehydrogenase; CRP, C-reactive protein.

*P < 0.05; **P < 0.01.