Use of social impact bonds in financing health systems responses to non-communicable diseases: scoping review.

There is an interest to understand how social impact bonds (SIBs), a type of innovative financing instrument used in impact investment, can be used to finance the prevention of non-communicable diseases (NCDs). This is the first scoping review that explores the evidence of SIBs for NCDs and their key characteristics and performance. The review used both published and grey literature from eight databases (MEDLINE, NCBI, Elsevier, Cochrane Library, Google, Google Scholar, WHO publications and OECD iLibrary). A total of 83 studies and articles were eligible for inclusion, identifying 11 SIBs implemented in eight countries. The shared characteristics of the SIBs used for NCDs were impact investment companies as investors, local governments as outcome payers, not-for-profit service providers and an average US$2 015 456 private initial investment. The review revealed a lack of empirical evidence on SIBs for NCDs. Conflict of interest and lack of public disclosure were common issues in both the published and grey literature on SIBs. Furthermore, only three SIBs implemented for financing NCDs were meeting all their target outcomes. The common characteristics of the SIBs meeting their target outcomes were evidence-based interventions, multiple service providers and an intermediated structure. Overall, there is a need for more high-quality studies, particularly economic evaluations and qualitative studies on the benefits to target populations, and greater transparency from the private sector, in order to ensure improved SIBs for preventing NCDs.