title: Predicting high vancomycin minimum inhibitory concentration isolate infection among patients with community-onset methicillin-resistant Staphylococcus aureus bacteraemia.
abstract: OBJECTIVE
  Methicillin-resistant Staphylococcus aureus (MRSA) isolates with an elevated vancomycin MIC ≥2 mg/L have been increasingly identified in many countries. We aimed to develop a clinical score to predict vancomycin MIC ≥2 mg/L in patients with community-onset MRSA bacteraemia.
  
  
  METHODS
  This retrospective cohort study enrolled 394 patients with MRSA bacteraemia. Vancomycin MICs of all MRSA isolates were determined by agar dilution method. Clinical characteristics between patients with high (≥2 mg/L) and low (≤1 mg/L) vancomycin MIC MRSA bacteraemia were compared. Independent predictors of high vancomycin MIC isolate infection were identified and used to create a score-based predictive model.
  
  
  RESULTS
  Among the 394 study patients, 56 (14.2%) had MRSA isolates with a vancomycin MIC ≥2 mg/L. The final regression model included 6 independent predictors: chronic liver disease (adjusted odds ratio [aOR], 2.99; 95% confidence interval [CI], 1.39-6.42), prior recovery of MRSA from respiratory tract specimen (aOR, 2.54; 95% CI, 1.15-5.61), end-stage renal disease (aOR, 2.53; 95% CI, 1.33-4.78), severe sepsis or septic shock on presentation (aOR, 2.39; 95% CI, 1.28-4.44), prior vancomycin exposure (aOR, 2.21; 95% CI, 1.13-4.30), and recent hospitalization within 3 months (aOR, 2.11; 95% CI; 1.01-4.40). All independent predictors had a value of one point. Youden's index statistics indicated a score of ≥3 as best cutoff value that had a sensitivity of 69.6% and specificity of 78.4%.
  
  
  CONCLUSIONS
  Simple decision rule helps clinicians stratify the risk of high vancomycin MIC MRSA infection when deciding empirical therapy for patients with community-onset infections.
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Shey-Ying
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Wen-Chu
authors.initials: WC
authors.lastname: Chiang
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Edward Pei-Chuan
authors.initials: EP
authors.lastname: Huang
authors.affiliation: Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ching-Feng
authors.initials: CF
authors.lastname: Lin
authors.affiliation: National Translational Medicine and Clinical Trial Resource Center, Taipei, Taiwan.
authors.forename: Chin-Hao
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shyr-Chyr
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wen-Jone
authors.initials: WJ
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shan-Chwen
authors.initials: SC
authors.lastname: Chang
authors.affiliation: Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Mei-Shu
authors.initials: MS
authors.lastname: Lai
authors.affiliation: Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan. Electronic address: weichu@ntu.edu.tw.
authors.forename: Wei-Chu
authors.initials: WC
authors.lastname: Chie
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology; D002908:Chronic Disease; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000382:microbiology; D003661:Decision Support Techniques; D005260:Female; D006760:Hospitalization; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D008107:Liver Diseases / Q000150:complications; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011237:Predictive Value of Tests; D012141:Respiratory Tract Infections / Q000150:complications / Q000382:microbiology; D012189:Retrospective Studies; D018805:Sepsis / Q000150:complications; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D014640:Vancomycin / Q000008:administration & dosage / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin
keywords: Bacteraemia; Community-onset; Methicillin-resistant Staphylococcus aureus; Minimum inhibitory concentration; Prediction rule