title: Comparative epidemiology of bacteremia due to methicillin-resistant Staphylococcus aureus between older and younger adults: a propensity score analysis.
abstract: OBJECTIVE
  We evaluated the clinical and molecular epidemiology of bloodstream infections (BSIs) due to methicillin-resistant Staphylococcus aureus (MRSA) in older versus younger patients treated with vancomycin, determining the independent effect of increased age on outcomes.
  
  
  METHODS
  Observational retrospective cohort study.
  
  
  METHODS
  Detroit Medical Center, level I trauma center.
  
  
  METHODS
  Adult older (65 years and older) and younger (younger than 65 years) patients with documented BSIs due to MRSA treated with vancomycin (2005-2010).
  
  
  METHODS
  Collected demographics, comorbidities, microbiology, treatment, outcomes. Multivariable model used to generate propensity score for each patient on the basis of the probability of being 65 years of age or older.
  
  
  RESULTS
  Three hundred twenty patients were eligible (69 patients 65 years and older; 251 patients younger than 65 years). Catheter-related infections and endocarditis were the most common sites of infection for older (20.3%) and younger (19.1%) adults, respectively. Median first total 24-hour vancomycin dose (1,000 vs 2,000 mg; [Formula: see text]) and initial trough (13.1 vs 15.0 mg/L; [Formula: see text]) was significantly lower in older versus younger patients. Vancomycin treatment failure rates were similar among older and younger patients (49.3% vs 53.4%; [Formula: see text]). In multivariable analysis of outcomes, after controlling for predictors of older age, there was no difference in clinical outcomes between older and younger adults.
  
  
  CONCLUSIONS
  After accounting for confounders associated with increased age, failure rate of patients with BSIs due to MRSA treated with vancomycin was similar between older and younger patients. Older adults were less likely to have optimal vancomycin dosing and initial trough levels than younger patients. Efforts should be made to optimize dosing of medications such as vancomycin in older adults.
authors: College of Pharmacy, Oregon State University/Oregon Health and Science University, Portland, OR 97239, USA. kullar@ohsu.edu
authors: Ravina
authors: R
authors: Kullar
authors: Michael J
authors: MJ
authors: Rybak
authors: Keith S
authors: KS
authors: Kaye
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008824:Michigan / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D057216:Propensity Score; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000453:epidemiology; D016896:Treatment Outcome; D014640:Vancomycin / Q000494:pharmacology / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin