Table 3.

Univariate and multivariate Cox models for 7-day mortality with clinical stage as time-dependent covariate

Covariables	Univariate analysis			Multivariate analysis
	HR	95% CI	P value	HR	95% CI	P value
Age (for each year of increase)	1.02	1.01 – 1.02	<0.001	1.01	1.00 – 101	0.039
Sex
Female	1	Reference		1	Reference
Male	1.02	0.81 – 1.27	0.875	0.98	0.76 – 1.27	0.899
Site
Community	1	Reference		1	Reference
Hospital	1.29	1.02 – 1.62	0.034	1.33	0.98 – 1.80	0.064
Source of infection
Urinary	1	Reference		1	Reference
Respiratory	2.70	1.85 – 3.95	<0.001	1.76	1.12 – 2.77	0.014
Skin and soft tissues	1.07	0.68 – 1.69	0.776	1.22	0.73 – 2.02	0.441
Intra-abdominal	2.36	1.52 – 3.65	<0.001	1.50	0.90 – 2.48	0.118
Other infections	2.34	1.65 – 3.31	<0.001	1.89	1.28 – 2.80	0.001
Comorbidities
Without comorbidities	1	Reference		1	Reference
With any comorbidity	1.52	1.17 – 1.98	0.002	0.88	0.65 – 1.20	0.426
SOFA score (0 – 24, for each unit of increase)	1.24	1.21 – 1.27	<0.001	1.09	1.04 – 1.15	0.001
APACHE II score (0 – 67, for each unit of increase)	1.13	1.11 – 1.14	<0.001	1.07	1.04 – 1.10	<0.001
Blood cultures
Not requested	1	Reference		1	Reference
Negative	1.07	0.82 – 1.40	0.603	0.91	0.67 – 1.23	0.546
Gram-positive bacteria	1.37	0.88 – 2.11	0.158	0.83	0.50 – 1.36	0.454
Gram-negative bacteria	1.04	0.68 – 1.58	0.858	0.59	0.36 – 0.95	0.031
Classification of infection (progression to)
Infection without sepsis	1	Reference		1	Reference
Sepsis	2.75	1.47 – 5.15	0.002	1.76	0.93 – 3.33	0.081
Severe sepsis	4.95	2.71 – 9.06	<0.001	2.13	1.13 – 4.03	0.019
Septic shock	13.51	7.41 – 24.64	<0.001	3.00	1.50 – 5.98	0.002