middle income High income Availability of nephrology training program by World Bank income group 0 10 20 30 40 50 60 70 80 90 100 Africa Eastern & Central Europe LaƟn America & the Caribbean Middle East NIS & Russia North America North & East Asia Oceania & South East Asia South Asia Western Europe 0 10 20 30 40 50 60 70 80 90 100 Following general internal medicine Solo training aŌer basic qualificaƟon A mix of 1 & 2 depending on region and/or training center Other Low income Lower middle income Upper middle income High income Structure of nephrology training by World Bank income group a b 0 10 20 30 40 50 60 70 80 90 100 Africa Eastern & Central Europe LaƟn America & the Caribbean Middle East NIS & Russia North America North & East Asia Oceania & South East Asia South Asia Western Europe Following general internal medicine Solo training aŌer basic qualificaƟon A mix of 1 & 2 depending on region and/or training center Other Figure 2 | (a) Availability of nephrology training programs in 121 countries. (b) Structure of nephrology training programs in 121 countries. (Continued) review MA Osman et al.: Health workforce for nephrology care: existing manpower and training capacity 56 Kidney International Supplements (2018) 8, 52–63 Global density of nephrology trainees. Similar to nephrologist density, there was significant variation in density of nephrology trainees among World Bank income groups and ISN regions (Table 1). Overall, the global density of nephrology trainees was 1.87 PMP. The prevalence of nephrology trainees in high-income countries was more than 30-fold that in low-income countries (6.03 vs. 0.18) (Table 1). The prevalence of nephrology trainees in lower-middle– and upper-middle–income level countries was 0.78 PMP and 1.19 PMP, respectively. Seven of the 10 countries with the lowest nephrology trainee densities were from the Africa ISN region, again sub-Saharan Africa specifically: Ethiopia, Uganda, Tanzania, Burundi, Ghana, Zambia, and Malawi. The other 3 countries were Indonesia and Cambodia (OSEA region) and Ukraine (NIS and Russia region). In contrast, the 10 countries with the highest nephrologist trainee densities were from different ISN regions, including 3 from the Africa ISN region, which contrasted sharply with the 7 African countries that were in the lowest density list. Japan (North and East Asia ISN region) reported the highest density followed by Kuwait (Middle East ISN region), Libya (Africa ISN region), Croatia (Eastern and Central Europe ISN region), Bahrain (Middle East ISN region), Serbia (Eastern and Central Europe ISN region), Norway (Western Europe ISN region), Greece (Western Europe ISN region), Algeria (Africa ISN region), and Egypt (Africa ISN region). In the Africa ISN region, all sub-Saharan countries reported trainee densities lower than the global average (1.87 PMP). Ethiopia (0.02 PMP), Uganda (0.05 PMP), and Tanzania (0.06 PMP) reported the lowest densities. North African countries reported the highest densities of trainees, with Libya (18.72 PMP) first followed by Algeria (9.10 PMP), Egypt (8.93 PMP), and Tunisia (5.44 PMP). In the Eastern and Central Europe ISN region, most of the countries reported trainee densities above the global average, with Slovakia (0.92 PMP) being the exception. The highest trainee density was reported by Croatia (13.44 PMP), followed by Serbia (9.75 PMP), Slovenia (7.56 PMP), and Lithuania (6.24 PMP). In the Latin America and the Caribbean ISN region, Colombia (0.43 PMP) and Peru (0.49 PMP) reported the lowest trainee density, followed by Costa Rica (0.62 PMP) and Chile (0.91 PMP). The highest density was reported by Argentina (5.76 PMP), Uruguay (4.79 PMP), Dominican Republic (3.15 PMP), and Brazil (2.20 PMP). In the Middle East ISN region, Kuwait (20.62 PMP), Bahrain (13.37 PMP), and Qatar (2.73 PMP) reported the highest trainee densities. Iran (0.26 PMP) and Iraq (0.32 PMP) reported the lowest densities. In the NIS and Russia ISN region, Armenia (3.44 PMP), Belarus (2.19 PMP), and Russia (2.11 PMP) reported trainee densities higher than the global average. In contrast, Ukraine (0.23 PMP) and Kazakhstan (0.83 PMP) reported trainee densities below the global average. In the North America ISN region, United States reported a nephrology trainee density (1.24 PMP) lower than the average Dura Ɵon of nephrology training by World Bank income group 0 90 80 70 60 50 40 30 20 10 100 Africa Eastern & Central Europe LaƟn America & the Caribbean Middle East NIS & Russia North America North & East Asia Oceania & South East Asia South Asia Western Europe < 2 years 2–4 years >4 years Dura Ɵon of nephrology training by ISN region Low Income Lower Middle Income Upper Middle Income High Income 100 90 80 70 60 50 40 30 20 10 0 4 Years c Figure 2 | (Continued) (c) Duration of nephrology training programs in 121 countries. MA Osman et al.: Health workforce for nephrology care: existing manpower and training capacity review Kidney International Supplements (2018) 8, 52–63 57 global density. In contrast, Canada (2.14 PMP) reported a density higher than the global average. In the North and East Asia ISN region, there was the greatest variation in trainee density within a region of all 10 ISN regions. Japan (35.46 PMP) reported one of the highest trainee densities globally, while Taiwan (5.56 PMP), Hong Kong