title: Validation of the bacterial meningitis score in adults presenting to the ED with meningitis.
abstract: OBJECTIVE
  The Bacterial Meningitis Score classifies children with meningitis and none of the following high-risk predictors at very low risk for bacterial meningitis: positive cerebrospinal fluid (CSF) Gram stain, CSF protein ≥80mg/dL, CSF absolute neutrophil count (ANC) ≥1000 cells/mm(3), peripheral ANC ≥10,000 cells/mm(3), and seizure at or prior to presentation. Although extensively validated in children, the Bacterial Meningitis Score has not been rigorously evaluated in adults.
  
  
  METHODS
  We performed a single-center cross-sectional retrospective study of adults presenting to the emergency department between 2003 and 2013 with meningitis (defined by CSF white blood cell count ≥10 cells/mm(3)). We defined a case of bacterial meningitis with either a positive CSF or blood culture. We report the performance of the Bacterial Meningitis Score in the study population.
  
  
  RESULTS
  We identified 441 eligible patients of which, 4 (1%) had bacterial meningitis. The Bacterial Meningitis Score had a sensitivity of 100% [95% confidence interval (CI) 40%-100%], specificity 51% (95% CI, 46%-56%) and negative predictive value of 100% (95% CI, 98%-100%). None of the low risk adults had bacterial meningitis. If Bacterial Meningitis Score had been applied prospectively, the hospital admission rate would have dropped from 84% to 49% without missing any patients with bacterial meningitis.
  
  
  CONCLUSIONS
  The Bacterial Meningitis Score accurately identified patients at low risk for bacterial meningitis and could assist clinical decision-making for adults with meningitis.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA; Department of Emergency Medicine, St. Luke's Hospital, New Bedford, MA. Electronic address: rmcarthu@bidmc.harvard.edu.
authors.forename: Robert
authors.initials: R
authors.lastname: McArthur
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Edlow
authors.affiliation: Division of Emergency Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA.
authors.forename: Lise E
authors.initials: LE
authors.lastname: Nigrovic
mesh_terms: D000328:Adult; D000367:Age Factors; D001772:Blood Cell Count; D000066491:Clinical Decision-Making; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D016920:Meningitis, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity