Research by the Global Burden of Disease Health Financing Collaborator Network produced projected health spending estimates for 2016-2040 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. GDP and all-sector government spending were extracted for 1980–2015 and used with retrospective health spending estimates for 1995-2015 to forecast GDP, all-sector government spending, and health spending through 2040. Results of the study were published in The Lancet in April 2018 in "Trends in future health financing and coverage: future health spending and universal health coverage in 188 countries, 2016–2040."