The impact of decentralisation on health systems: a systematic review of reviews.

Background: Decentralisation is a common mechanism for health system reform; yet, evidence of how it impacts health systems remains fragmented. Despite published findings from primary and secondary research illustrating range of impacts, a comprehensive and clear understanding is currently lacking. This review synthesised the existing evidence to assess how decentralisation (by devolution) impacts each of the six WHO building blocks, and the health system.