Abstract: We included 25 studies involving 4121 participants (2511 children and 1517 adults; 93 mixed population). Four studies were of high quality with no risk of bias, 14 of medium quality and seven of low quality, indicating a moderate risk of bias for the total analysis. Nine studies were performed in low-income countries and 16 in high-income countries. There was insufficient evidence that corticosteroids caused a reduction in mortality overall (17.8% versus 19.9%; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.80 to 1.01; P = 0.07), or for adults (RR 0.74, 95% CI 0.53 to 1.05; P = 0.09). However they caused lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.74, 95% CI 0.63 to 0.87) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00). Subgroup analyses for causative organisms showed that corticosteroids reduced mortality in Streptococcus pneumoniae (S pneumoniae) meningitis (RR 0.84, 95% CI 0.72 to 0.98), but not in Haemophilus influenzae (H influenzae) orNeisseria meningitidis (N meningitidis) meningitis. Corticosteroids reduced severe hearing loss in children with H influenzae meningitis (RR 0.34, 95% CI 0.20 to 0.59) but not in children with meningitis due to non-Haemophilus species. In high-income countries, corticosteroids reduced severe hearing loss (RR 0.51, 95% CI 0.35 to 0.73), any hearing loss (RR 0.58, 95% CI 0.45 to 0.73) and short-term neurological sequelae (RR 0.64, 95% CI 0.48 to 0.85). There was no beneficial effect of corticosteroid therapy in low-income countries. Subgroup analysis for study quality showed no effect of corticosteroids on severe hearing loss in high-quality studies. Corticosteroid treatment was associated with an increase in recurrent fever (RR 1.27, 95% CI 1.09 to 1.47), but not with other adverse events. Corticosteroids significantly reduced hearing loss and neurological sequelae, but did not reduce overall mortality. Data support the use of corticosteroids in patients with bacterial meningitis in high-income countries. We found no beneficial effect in low-income countries.

Plain-language summary: The evidence is current to February 2015. We identified 25 trials, including 4121 participants with acute bacterial meningitis of which seven were performed in adults (over 16 years old), two included both children and adults and the other were performed in children. In 22 studies the corticosteroid used was dexamethasone, in three others hydrocortisone or prednisone were used. Nine studies were performed in low-income countries and 16 in high-income countries. This review found that the corticosteroid dexamethasone did not significantly reduce the death rate (17.8% versus 19.9%). Patients treated with corticosteroids had significantly lower rates of severe hearing loss (6.0% versus 9.3%), any hearing loss (13.8% versus 19.0%) and neurological sequelae (17.9% versus 21.6%). An analysis for different bacteria causing meningitis showed that patients with meningitis due to Streptococcus pneumoniae (S pneumoniae) treated with corticosteroids had a lower death rate (29.9% versus 36.0%), while no effect on mortality was seen in patients with Haemophilus influenzae (H influenzae) and Neisseria meningitidis (N meningitidis) meningitis. In high-income countries, corticosteroids reduced severe hearing loss, any hearing loss and short-term neurological sequelae. There was no beneficial effect of corticosteroid therapy in low-income countries. Corticosteroids decreased the rate of hearing loss in children with meningitis due to H influenzae (4% versus 12%), but not in children with meningitis due to other bacteria. Dexamethasone increased the rate of recurrent fever (28% versus 22%) but was not associated with other adverse events. Out of 25 studies, four were of high quality, 14 of medium quality and seven of low quality, leading to a moderate overall quality of evidence.