Clinical index to predict bacteraemia caused by staphylococci.
OBJECTIVE
To define risk factors associated with bacteraemia caused by Staphylococcus aureus or coagulase-negative staphylococci; and to use them to define patients in need of empiric anti-staphylococcal antibiotic treatment.


METHODS
Derivation set: observational, prospective study; validation set: retrospective analysis of a prospectively collected database.


METHODS
Derivation set: Beilinson Medical Centre, Petah Tiqva, Israel--a 900-bed university hospital. Validation set: St Thomas's Hospital, London, UK--an 800-bed teaching hospital.


METHODS
All episodes of bacteraemia detected at Beilinson Medical Centre between March 1988 and September 1990 (derivation set, n = 1410), and at St Thomas's Hospital during 1987-1990 (validation set, n = 1040).


METHODS
None.


METHODS
Percentage of staphylococcal bacteraemia in groups of patients defined by the models.


RESULTS
The following factors were associated with Staphylococcus aureus bacteraemia: focus of infection (whether high or low risk), haemodialysis, intravenous drug abuse and infection acquired in the orthopaedic ward. A logistic model was used to divide the derivation set into three groups with percentages of Staphylococcus aureus bacteraemia of 1.8%, 13.2% and 33.7% (P < 0.0001); and the validation group 2.5%, 18.2% and 53.2% (P < 0.0001). Factors associated with coagulase-negative staphylococcal bacteraemia were: central or peripheral intravenous catheter as the focus of infection, a preterm neonate, the presence of a central intravenous catheter, low temperature, and a low white blood cell count. A second model including those factors was used to divide the derivation set into three groups with percentages of coagulase-negative staphylococcal bacteraemia of 1.9%, 22.8%, and 43% (P < 0.0001). In the validation set, the percentages were 2.9%, 22.4% and 31.0% (P < 0.001).


CONCLUSIONS
The present study defines groups at high risk for staphylococcal bloodstream infection, in which empiric treatment should include an anti-staphylococcal drug.
Leibovici
L
L
Department of Medicine B, Beilinson Medical Centre, Petah Tiqva, Israel.
Gransden
W R
WR
Eykyn
S J
SJ
Konsiberger
H
H
Drucker
M
M
Pitlik
S D
SD
Phillips
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000209:etiology* / Q000382:microbiology / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000209:etiology* / Q000382:microbiology / Q000517:prevention & control