Table 5.

Predictors for survival by univariate and multivariate Cox regression models in IPF patients.

Clinical Variables	Univariate Cox Model			Multivariate Cox Model
	HR	95.0% CI	p-value	HR	95.0% CI	p-value
Concurrent infection	3.052	1.726-5.398	<0.001	1.461	0.763-2.797	0.253
PaO2/FiO2 ratio	0.989	0.986-0.993	<0.001	0.991	0.986-0.996	<0.001
CT score	1.664	1.400-1.978	<0.001	1.115	0.868-1.432	0.396
Serum GDF-15 (>1,075.76 pg/ml)	0.341	0.195-0.598	<0.001	0.428	0.232-0.790	0.007