The authors used safety data from 31 randomised controlled trials comparing oral systemic steroids (prednisone, prednisolone) or steroids with low systemic bioavailability (budesonide, budesonide multi-matrix system (MMX), beclomethasone) with placebo, or against each other. Budesonide MMX was shown to be associated with fewer corticosteroid-related adverse events than all comparators apart from budesonide, for which the difference was not statistically significant (OR 0.64, 95% CI 0.37–1.11). There were no differences seen between treatments in the occurrence of serious adverse events, and treatment discontinuations due to adverse events.
They acknowledge several limitations of their review, including a high or unclear risk of bias in the majority of the included studies, and the enrolment of selective populations (as many were registration studies), thus potentially limiting external validity (e.g. elderly under-represented). They conclude that “further high-quality research is warranted to illuminate the steroid drugs' comparative safety profiles.”