Table 3. Univariate log-rank analysis and multivariate Cox proportional hazard regression analysis.

	Log-rank test		multivariate COX proportional hazard regression
	P value		coef	exp(coef) (95% CI)	z	P value
Model 1
age	<0.01		0.03	1.03 (1.01, 1.04)	3.86	<0.01***
gender	0.03		−0.30	0.74 (0.51, 1.08)	−1.56	0.12
Smoking status	0.9		−0.34	0.71 (0.37, 1.35)	−1.05	0.30
Comorbidities	<0.01		0.61	1.84 (1.23, 2.73)	3.00	<0.01**
Duration from symptom onset to confirmation >5 days	<0.01		0.53	1.69 (1.10,2.60)	2.40	0.01*
Model 2
age	<0.01		0.03	1.03 (1.01, 1.04)	3.91	<0.01***
gender	0.03		−0.29	0.75 (0.51, 1.11)	−1.45	0.14
Smoking status	0.90		−0.47	0.63 (0.31, 1.26)	−1.31	0.19
Comorbidities	<0.01		0.57	1.77 (1.18, 2.68)	2.73	<0.01**
Duration from symptom onset to first visit >4 days	<0.01		0.44	1.56 (1.07, 2.26)	2.34	0.02*
Duration from first visit to confirmation >3 days	<0.01		0.37	1.45 (0.99, 2.13)	1.89	0.06#

***P<0.001; **P<0.01; *P<0.05; ^#P<0.1.