Relative efficacy of cefuroxime versus dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia: a propensity-score adjusted retrospective cohort study.
OBJECTIVE
The objective of the present study was to compare the efficacy of cefuroxime with that of dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia (MS-SAB) using a Danish bacteraemia database, information on the indication for antimicrobial therapy, multivariate adjustment and propensity score (PS) matching.


METHODS
This was a retrospective cohort study. MS-SAB cases from 1 January 2006 to 31 December 2008 were included from a total of seven hospitals in the greater Copenhagen area and seven hospitals in the North Denmark Region. Information including demographics, antimicrobial therapy and clinical condition was obtained. The physician's note detailing the indication for starting empirical antimicrobial therapy was given special attention. Hazard ratios (HRs) and 95% CIs for 30 day and 90 day mortality were calculated using PS-adjusted Cox proportional hazards regression analyses. In addition, PS matching was performed.


RESULTS
A total of 691 patients with MS-SAB received either dicloxacillin (n = 368) or cefuroxime (n = 323) as definitive antimicrobial therapy. Twenty-eight different indications for empirical antimicrobial therapy were identified and grouped into eight categories. There was no statistically significant difference in 30 day mortality between the two groups (HR 1.02, 95% CI 0.68-1.52). Definitive antimicrobial therapy with cefuroxime was associated with increased 90 day mortality in a PS-adjusted multivariate analysis (HR 1.43, 95% CI 1.03-1.98) and in the PS matching (OR 1.65, 95% CI 1.06-2.56). Antimicrobial therapy for an indication of 'severe infection' was independently associated with 90 day mortality (HR 1.97, 95% CI 1.19-3.28).


CONCLUSIONS
Definitive antimicrobial therapy with cefuroxime was associated with significantly higher 90 day mortality than was dicloxacillin therapy in patients with MS-SAB.
Department of Clinical Microbiology, Copenhagen University Hospital, Hvidovre, Denmark.
Jon Bjarke
JB
Rasmussen
Jenny Dahl
JD
Knudsen
Magnus
M
Arpi
Henrik Carl
HC
Schønheyder
Thomas
T
Benfield
Christian
C
Ostergaard
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000175:diagnosis / Q000188:drug therapy*; D002444:Cefuroxime / Q000494:pharmacology / Q000627:therapeutic use*; D015331:Cohort Studies; D004009:Dicloxacillin / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008712:Methicillin / Q000494:pharmacology / Q000627:therapeutic use; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D008875:Middle Aged; D057216:Propensity Score; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D004009:Dicloxacillin; D002444:Cefuroxime; D008712:Methicillin
S. aureus; sepsis; septicaemia epidemiology; β-lactams