title: Effects of inappropriate empirical antibiotic therapy on mortality in patients with healthcare-associated methicillin-resistant Staphylococcus aureus bacteremia: a propensity-matched analysis.
abstract: BACKGROUND
  The purported value of empirical therapy to cover methicillin-resistant Staphylococcus aureus (MRSA) has been debated for decades. The purpose of this study was to evaluate the effects of inappropriate empirical antibiotic therapy on clinical outcomes in patients with healthcare-associated MRSA bacteremia (HA-MRSAB).
  
  
  METHODS
  A prospective, multicenter, observational study was conducted in 15 teaching hospitals in the Republic of Korea from February 2010 to July 2011. The study subjects included adult patients with HA-MRSAB. Covariate adjustment using the propensity score was performed to control for bias in treatment assignment. The predictors of in-hospital mortality were determined by multivariate logistic regression analyses.
  
  
  RESULTS
  In total, 345 patients with HA-MRSAB were analyzed. The overall in-hospital mortality rate was 33.0 %. Appropriate empirical antibiotic therapy was given to 154 (44.6 %) patients. The vancomycin minimum inhibitory concentrations of the MRSA isolates ranged from 0.5 to 2 mg/L by E-test. There was no significant difference in mortality between propensity-matched patient pairs receiving inappropriate or appropriate empirical antibiotics (odds ratio [OR] = 1.20; 95 % confidence interval [CI] = 0.71-2.03). Among patients with severe sepsis or septic shock, there was no significant difference in mortality between the treatment groups. In multivariate analyses, severe sepsis or septic shock (OR = 5.45; 95 % CI = 2.14-13.87), Charlson's comorbidity index (per 1-point increment; OR = 1.52; 95 % CI = 1.27-1.83), and prior receipt of glycopeptides (OR = 3.24; 95 % CI = 1.08-9.67) were independent risk factors for mortality.
  
  
  CONCLUSIONS
  Inappropriate empirical antibiotic therapy was not associated with clinical outcome in patients with HA-MRSAB. Prudent use of empirical glycopeptide therapy should be justified even in hospitals with high MRSA prevalence.
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Kyung
authors.initials: YK
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jang Wook
authors.initials: JW
authors.lastname: Sohn
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Won Ju, Republic of Korea.
authors.forename: Hyo Youl
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chungnam National University Hospital, Daejon, Republic of Korea.
authors.forename: Yeon-Sook
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Chang-Seop
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Republic of Korea.
authors.forename: Mi Suk
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Keimyung University Dongsan Hospital, Daegu, Republic of Korea.
authors.forename: Seong-Yeol
authors.initials: SY
authors.lastname: Ryu
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Hee-Chang
authors.initials: HC
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, National Cancer Center, Seoul, Republic of Korea.
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Cheol-In
authors.initials: CI
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Ewha Women's University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors.forename: Seung Soon
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Shin Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Catholic University of Korea, College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul, Republic of Korea.
authors.forename: Eu Suk
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Samyook Medical Center, Seoul, Republic of Korea.
authors.forename: Jeong Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Biostatistics, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung Sook
authors.initials: KS
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea. macropha@korea.ac.kr.
authors.forename: Min Ja
authors.identifier: http://orcid.org/0000-0001-8435-935X
authors.initials: MJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D016022:Case-Control Studies; D003428:Cross Infection / Q000382:microbiology; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D016015:Logistic Models; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D057216:Propensity Score; D011446:Prospective Studies; D056910:Republic of Korea; D012307:Risk Factors; D018805:Sepsis / Q000188:drug therapy / Q000401:mortality; D014640:Vancomycin / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin
keywords: Anti-bacterial agents; Bacteremia; Methicillin-resistant Staphylococcus aureus; Risk factors; Treatment outcome