Abstract

Objectives

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 ≥80 mg/dL, CSF absolute neutrophil count (ANC) ≥ 1000 cells/mm³, peripheral ANC ≥ 10,000 cells/mm³ 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/mm³). 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.