A Cochrane review included 12 studies with a total of 863 subjects. Early use of corticosteroids significantly reduced admission rates (pooled OR 0.40, 95% CI 0.21 to 0.78), NNT = 8. Oral corticosteroid therapy in children was particularly effective (OR 0.24, 95% CI 0.11 to 0.53).
Nine trials with a total of 344 patients were included in a Cochrane review (abstract , review ): 96 patients with low dose (<= 80 mg of methylprednisolone/day), 85 with medium dose (80 - 360 mg of methylprednisolone), and 163 with high dose (more than 360 mg of prednisolone) corticosteroids. Six trials were eligible for meta-analysis. No differences were identified in lung function improvement among the different doses of corticosteroids.
A third systematic review including 16 studies with a total of nearly 1000 subjects was abstracted in DARE. At the 3-hour assessment, only high doses of inhaled corticosteroids significantly improved pulmonary function compared with placebo (effect size = 0.56, 95% CI 0.15 to 0.97). After receiving intravenous corticosteroids, patients required at least 6 to 24 hours to show moderate but nonsignificant improvements in pulmonary function: 6-hour effect size = 0.44, 95% CI -0.01 to 0.89). The data from 6 studies suggested a 32% reduction of admission rate in favour of corticosteroids (RR 0.68, 95% CI 0.47 to 0.99, NNT = 12.5), but the pooled effect of the 3 high-quality studies showed no difference between groups (RR 1.21, 95% CI 0.67 to 2.18).