Predisposing factor, impactful adjunctive treatment or unfavorable prognostic marker: a meta-analysis on the elusive role of dexamethasone for Listeria monocytogenes meningitis

Introduction: There are no randomized controlled trials to inform the choice of using adjunctive dexamethasone (AD) against Listeria monocytogenes meningitis (LMM) and data from observational studies are pretty conflicting. Methodology: We performed a rapid review of the literature with quantitative analysis. A pairwise random-effects meta-analysis was implemented, pooling unadjusted and adjusted data. The main outcome was mortality. Results: Across all included studies (five) informing the main analysis on raw mortality data, 199 patients received AD, as opposed to 382 who did not receive AD. All-cause mortality was slightly lower in patients undergoing AD, but not in a statistically significant manner: odds ratio 0.96, 95% confidence interval 0.42-2.19. The prediction interval was very wide (0.06-15.99), suggesting that in future studies the effect of AD might be either beneficial or harmful. Conclusions: The role of AD for LMM still needs to be established being the current evidence inconclusive and heterogeneous.