Risk of mortality with a bloodstream infection is higher in the less severely ill at admission.

VA Maryland Health Care System, 100 N. Greene St. (Lower level), Baltimore, MD 21201, USA.
American Journal of Respiratory and Critical Care Medicine (Impact Factor: 11.04). 04/2005; 171(6):616-20. DOI: 10.1164/rccm.200407-916OC
Source: PubMed

ABSTRACT 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.
To estimate the impact of health care-associated bloodstream infections on in-hospital mortality after adjusting for severity of illness at critical care admission.
A cohort of medical and surgical intensive care unit patients.
Severity of illness at admission, bloodstream infection, and in-hospital mortality.
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.
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.

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