TABLE 4.

Multivariable Cox regression analysis of clinical and bacterial factors influencing Staphylococcus aureus and Gram-negative bloodstream infection mortality in inpatients at Duke University Medical Center from 2002 to 2015^a

Parameter	Hazard ratio	95% CI	P
Age	1.376	1.286–1.475	<0.0001
Female gender	1.129	0.936–1.359	0.203
Raceb
Black	1.223	0.991–1.501	0.058
Other	0.804	0.485–1.253	0.366
Pseudomonas aeruginosa BSI	1.435	1.043–1.933	0.021
APACHE-II chronic health score	1.168	1.101–1.244	<0.0001
MDR	1.051	0.869–1.269	0.609
Appropriate antibiotic therapyc	1.435	0.967–2.202	0.085
Days to line removald
1	0.537	0.192–1.305	0.194
2	0.606	0.232–1.424	0.271
≥3	0.904	0.259–2.468	0.857
No line-associated infection	7.227	0.392–37.881	0.060
BSI era (2005-2015)e	2.581	1.863–3.690	<0.0001
BSI sourcef
Biliary	0.607	0.303–1.105	0.127
Pneumonia	2.264	1.628–3.169	<0.0001
Line	5.411	0.299–26.650	0.103
Skin/soft tissue	0.531	0.322–0.847	0.010
Abscess	0.721	0.387–1.254	0.273
Other	1.035	0.726–1.476	0.850
Source not identified	2.073	1.549–2.810	<0.0001

^aAbbreviations: BSI, bloodstream infection; CI, confidence interval; MDR, multidrug resistant. Statistically significant values are indicated in boldface.

^bThe reference group was composed of white patients.

^cThis is a time-dependent variable in which “no appropriate antibiotic therapy” is the reference.

^dThe reference group is composed of patients with line-associated infections and line removal on day 0.

^eThe reference group is composed of BSI from 2002 to 2004.

^fThe reference group is BSI from a urine/pyelonephritis source.