LAUSR

We read with interest a recent publication in Health olicy where Sumah et al. [1] conducted a systematic eview of the “impacts” of decentralisation on healthelated equity. This is as a highly-welcomed contribution o better understand how health systems across the world ave strengthened (or weakened) after implementing varous forms of decentralisation in the health sector. In the eer-reviewed literature, we are aware of only two other ecent systematic reviews on health sector decentralisaion. The Cochrane Collaboration’s Effective Practice and rganisation of Care Group (EPOC) Group has published review protocol that aims to assess the effectiveness of ecentralisation in improving access to health care, utilsation of health services, population health, and other utcomes of interest [2], although its final report has not een published as of this writing. A systematic review in nother peer-reviewed journal has examined the impacts f decentralisation in low and middle-income countries sing the “six building blocks of health systems” frameork of the World Health Organization and finds both ositive and negative effects in the six building blocks and, herefore, mixed results [3]. Building on Sumah’s work, this letter expands on elected aspects emerging from the review, namely: (a) hat does impact in the context of decentralisation mean?; b) how should we assess a complex intervention?; and (c) hat are the possible ways forward for studies on decenralisation?