Risk of mortality with a bloodstream infection is higher in the less severely ill at admission.
BACKGROUND
Health care-associated bloodstream infections are common in critically ill patients; however, investigators have had difficulty in quantifying the clinical impact of these infections given the high expected mortality among these patients.


OBJECTIVE
To estimate the impact of health care-associated bloodstream infections on in-hospital mortality after adjusting for severity of illness at critical care admission.


METHODS
A cohort of medical and surgical intensive care unit patients.


METHODS
Severity of illness at admission, bloodstream infection, and in-hospital mortality.


RESULTS
Among the 2,783 adult patients, 269 developed unit-associated bloodstream infections. After adjusting for severity of illness, patients with a lower initial severity of illness who developed an infection had a greater than twofold higher risk for in-hospital mortality (hazard ratio [HR] = 2.42, 95% confidence interval [CI] 1.70, 3.44) when compared with patients without infection and with a similar initial severity of illness. In contrast, patients with a higher initial severity of illness who subsequently developed an infection did not have an increased risk for in-hospital mortality (HR = 0.96, 95%CI 0.76, 1.23) when compared with patients without infection but with a similar initial severity of illness.


CONCLUSIONS
These results suggest that these infections in less ill patients have a higher attributable impact on subsequent mortality than in more severely ill patients. Focusing interventions to prevent bloodstream infections in less severely ill patients would be expected to have a greater benefit in terms of mortality reduction.
Kim
Peter W
PW
VA Maryland Health Care System, 100 N. Greene St. (Lower level), Baltimore, MD 21201, USA.
Perl
Trish M
TM
Keelaghan
Eithne F
EF
Langenberg
Patricia
P
Perencevich
Eli N
EN
Harris
Anthony D
AD
Song
Xiaoyan
X
Roghmann
Mary-Claire
MC
D018806:APACHE; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D018805:Sepsis / Q000401:mortality* / Q000517:prevention & control