Dexamethasone treatment and prognostic factors in community-acquired bacterial meningitis: a Danish retrospective population-based cohort study.

Introduction: The morbidity and mortality in community-acquired bacterial meningitis (CABM) remain substantial and treatment outcomes and predictors of a poor prognosis must be assessed regularly. We aimed to describe the outcome of patients with CABM treated with dexamethasone and to assess the performance of the Dutch Meningitis Risk Score (DMRS).

Methods: We retrospectively evaluated all adults with CABM in North Denmark Region, 1998-2012. Outcomes included in-hospital mortality and Glasgow Outcome Scale (GOS) score. A GOS score of 5 was categorized as a favourable outcome and scores of 1-4 as unfavourable. We used logistic analysis to compute relative risks (RRs) with 95% confidence intervals (CIs) for an unfavourable outcome adjusted for age, sex, and comorbidity.

Results: We identified a total of 172 cases of CABM. In-hospital mortality was unaffected by the implementation of dexamethasone in 2003 (19% vs 20%). Dexamethasone treatment was associated with a prompt diagnosis of meningitis and a statistically insignificant decrease in the risk of an unfavourable outcome (33% vs 53%; adjusted RR 0.64, 95% CI 0.41-1.01) and in-hospital mortality (15% vs 24%; adjusted RR 0.72, 95% CI 0.35-1.48). Of the risk factors included in the DMRS, we found age and tachycardia to be significantly associated with an unfavourable outcome in the multivariate analyses.

Conclusions: Patients treated with dexamethasone were more likely to have a favourable outcome, although statistical significance was not reached. Several parameters included in the Dutch risk score were also negative predictors in our cohort, although the entire risk score could not be validated due to a lack of data.