Role of comorbidity in mortality related to Staphylococcus aureus bacteremia: a prospective study using the Charlson weighted index of comorbidity.
OBJECTIVE
To demonstrate the effectiveness of the Charlson weighted index of comorbidity (WIC) for controlling comorbidity in prospective studies focusing on mortality in patients with Staphylococcus aureus bacteremia (SAB).


METHODS
Cohort study.


METHODS
Two tertiary-care, university-affiliated hospitals in France.


METHODS
One hundred sixty-six inpatients 18 years or older consecutively diagnosed with SAB from May 15, 2001, to May 15, 2002.


METHODS
Patients were prospectively assessed and cases were followed by the infectious diseases consult service at least 3 months after effective antibiotic therapy completion. The Charlson WIC was computed and dichotomized into scores of fewer than 3 points and 3 or more points. Bacteremia source, acute complication due to SAB acquisition in the ICU, and inappropriate empiric antibiotic therapy were recorded. The endpoint was death due to SAB and overall mortality.


RESULTS
In univariate analysis, the Charlson WIC was able to predict overall mortality and S. aureus-related death. The following variables were found to be independently predictive of mortality due to SAB using the Cox model: an acute complication due to S. aureus (OR, 8.9; CI95, 4 to 19.7; P < .001), a Charlson WIC score of 3 or more (OR, 3; CI95, 1.3 to 5.5; P = .006), and age (OR, 1.04; CI95, 1.009 to 1.07; P < .01).


CONCLUSIONS
Comorbidity contributes to death in patients with SAB. The Charlson WIC is a good predictor of mortality in this population and may be a useful instrument to control comorbidity in studies aiming to investigate risk factors for death due to bacteremia.
Lesens
Olivier
O
Service des Maladies Infectieuses et Tropicales, Clinique Médicale A, Hôpitaux Universitaires, Strasbourg, France.
Methlin
Cédric
C
Hansmann
Yves
Y
Remy
Véronique
V
Martinot
Martin
M
Bergin
Colm
C
Meyer
Pierre
P
Christmann
Daniel
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D002408:Catheters, Indwelling / Q000382:microbiology; D015897:Comorbidity; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D004697:Endocarditis, Bacterial / Q000188:drug therapy / Q000401:mortality; D005260:Female; D005602:France / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D013211:Staphylococcus aureus / Q000187:drug effects; D016019:Survival Analysis; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents