Ibadan, Nigeria; 26Division Epidemiologia, Direccion General de Salud–Ministerio Salud Publica, Montevideo, Uruguay; 27Nephrology Development Clinical Center, Tbilisi State Medical University, Tbilisi, Georgia; 28Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; 29Department of Internal Disease and Nephrology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia; 30Department of Nephrology and Dialysis, Pavlov First St. Petersburg State Medical University, St. Petersburg, Russia; 31Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; 32Key Lab of Renal Disease, Ministry of Health of China, Beijing, China; 33Key Lab of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; and 34Peking-Tsinghua Center for Life Sciences, Beijing, China The health workforce is the cornerstone of any health care system. An adequately trained and sufficiently staffed workforce is essential to reach universal health coverage. In particular, a nephrology workforce is critical to meet the growing worldwide burden of kidney disease. Despite some attempts, the global nephrology workforce and training capacity remains widely unknown. This multinational cross-sectional survey was part of the Global Kidney Health Atlas project, a new initiative administered by the International Society of Nephrology (ISN). The objective of this study was to address the existing global nephrology workforce and training capacity. The questionnaire was administered online, and all data were analyzed and presented by ISN regions and World Bank country classification. Overall, 125 United Nations member states responded to the entire survey, with 121 countries responding to survey questions pertaining to the nephrology workforce. The global nephrologist density was 8.83 per million population (PMP); high-income countries reported a nephrologist density of 28.52 PMP compared with 0.31 PMP in low-income countries. Similarly, the global nephrologist trainee density was 1.87 PMP; Correspondence: A.K. Bello, Division of Nephrology and Immunology, Department of Medicine, University of Alberta, 11-107 Clinical Sciences Building, 8440 112 Street NW, Edmonton, Alberta T6B 2B7, Canada. E-mail: aminu1@ualberta.ca 35Co-chairs, Global Kidney Health Atlas Project. review www.kisupplements.org 52 Kidney International Supplements (2018) 8, 52–63 high-income countries reported a 30 times greater nephrology trainee density than low-income countries (6.03 PMP vs. 0.18 PMP). Countries reported a shortage in all care providers in nephrology. A nephrology training program existed in 79% of countries, ranging from 97% in high-income countries to 41% in low-income countries. In countries with a training program, the majority (86%) of programs were 2 to 4 years, and the most common training structure (56%) was following general internal medicine. We found significant variation in the global density of nephrologists and nephrology trainees and shortages in all care providers in nephrology; the gap was more prominent in low-income countries, particularly in African and South Asian ISN regions. These findings point to significant gaps in the current nephrology workforce and opportunities for countries and regions to develop and maintain a sustainable workforce. Kidney International Supplements (2018) 8, 52–63; https://doi.org/10.1016/ j.kisu.2017.10.009 KEYWORDS: acute kidney injury; chronic kidney disease; education and training; health manpower; nephrology; workforce Copyright ª 2017, International Society of Nephrology. Published by Elsevier Inc. All rights reserved. Health workforce, in general, is the cornerstone of a country’s health care system.1 Countries cannot reach universal health coverage2 and sustainable development goals3 without an investment in human resources. To achieve that, countries need adequate numbers of qualified workforce members delivering and managing their health care system. A nephrology workforce in particular is critical to meet the growing worldwide burden of kidney disease4–6 and its risk factors, such as diabetes,7 obesity,8 and an aging population,9 and the increasing demand of renal replacement therapy (RRT) and kidney care in both high-income and lowincome countries.10 Indeed, nephrologist caseload was found to be associated with mortality of dialysis patients.11 Various studies have already examined the state of the nephrology workforce, highlighting the gaps and deficiencies in workforce availability and quality.12–18 In 1 review of the global nephrology workforce, Sharif et al.12 identified multiple factors responsible for the global shortage in the nephrology workforce and suggested a detailed and comprehensive nephrology workforce planning that is backed by government policy and legislation to ensure effective delivery and sustainability of kidney disease care. Another study that examined kidney care structures across 17 European countries identified limited workforce capacity, among many others, as a common barrier to the care of people with non–dialysisdependent chronic kidney disease (CKD).13 The objective of this cross-sectional survey that was