Betamethasone and dexamethasone in adult community-acquired bacterial meningitis: a quality registry study from 1995 to 2014

Acute bacterial meningitis (ABM) is a highly lethal disease. Available data support the use of corticosteroids in high-income countries, but the effect on mortality is still controversial. The effects of corticosteroids on mortality and sequelae were evaluated in the national Swedish quality registry. In total, during 1995-2014 1746 adults with ABM were included, of whom 989 were treated with corticosteroids (betamethasone, n = 766; dexamethasone, n = 248; methylprednisolone, n = 2), 498 were not given corticosteroids and in 259 patients data for corticosteroids were missing. Fatal outcome was observed in 8.9% of the patients in the corticosteroid-treated group vs. 17.9% in the non-corticosteroid-treated group (p <0.001), resulting in an odds ratio (OR) of 0.57 with a 95% confidence interval (CI) of 0.40-0.81 adjusted for age, sex, mental status, and door-to-antibiotic time. In patients with meningitis caused by S. pneumoniae, mortality was 10.2% in the corticosteroid-treated group and 21.3% in the non-corticosteroid-treated group (p <0.001) with an adjusted OR of 0.50 (95% CI 0.31-0.80). In ABM patients with non-pneumococcal aetiology the adjusted OR was 0.71 (95% CI 0.40-1.26). Lower mortality was observed in the corticosteroid-treated group with impaired mental status, whereas no significant difference was found in patients with unaffected mental status. The adjusted ORs for betamethasone and dexamethasone were 0.49 (95% CI 0.28-0.84) and 0.61 (95% CI 0.37-1.01), respectively. Corticosteroid treatment decreases mortality in ABM and should be administered initially with antibiotics in adult ABM patients with impaired mental status regardless of presumed aetiology. Betamethasone seems to be at least as effective as dexamethasone.