Research by the Global Burden of Disease Health Financing Collaborator Network produced retrospective national health spending estimates for 1995-2015 for 188 countries. The estimates cover total health spending, and health spending disaggregated by source into government spending, out-of-pocket, prepaid private, and development assistance for health. National health spending by source, including development assistance for health, was estimated based on a diverse set of data, including program reports, budget data, national estimates, and National Health Accounts. The resulting estimates were used to help produce prospective health spending estimates for 2016-2040. Results of the analysis were published in The Lancet in April 2018 in "Spending on health and HIV/AIDS: domestic health spending and development assistance in 188 countries, 1995-2015."