title: Risk of mortality with a bloodstream infection is higher in the less severely ill at admission.
abstract: 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.
authors.affiliation: VA Maryland Health Care System, 100 N. Greene St. (Lower level), Baltimore, MD 21201, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kim
authors.forename: Trish M
authors.initials: TM
authors.lastname: Perl
authors.forename: Eithne F
authors.initials: EF
authors.lastname: Keelaghan
authors.forename: Patricia
authors.initials: P
authors.lastname: Langenberg
authors.forename: Eli N
authors.initials: EN
authors.lastname: Perencevich
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Harris
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Song
authors.forename: Mary-Claire
authors.initials: MC
authors.lastname: Roghmann
mesh_terms: 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