Other aspects of renal service provision also vary markedly between countries. Big differences in the rates of home dialysis – peritoneal dialysis and home haemodialysis – are unlikely to be explained solely by medical differences in the patient population. (5) And while treatment factors clearly play a major role in determining patient survival on RRT, the association between non-medical factors and variation in survival on RRT around the world (6, 7) has never been examined.

The EVEREST study is an international collaborative project involving nephrologists, epidemiologists and health economists in different countries aiming to determine how much of the variation in RRT incidence, dialysis modality mix and patient survival is due to economic and organisational factors rather than medical factors. Data have been collected from three sources:

• Secondary data sources: The WHO Health For All and OECD databases will provide information on macroeconomic factors (national wealth and health care spending), health care resources, and population health (life expectancy, ischaemic heart disease rates, diabetes rates etc)
• Renal registries: These will be asked to provide data on trends in RRT incidence (including rates of diabetic nephropathy), modality mix and survival on RRT.
• Expert opinion: National experts on renal service provision will provide information on the organisation of health care systems and renal services, reimbursement of dialysis facilities and physicians, referral to a nephrologist and non-dialysis therapy.

Renal registries and national experts in 43 countries have now contributed data to the study and we are extremely grateful to all these individuals for their willing collaboration. The renal registry, national expert and economic datasets are in the process of being merged and analyses are set to begin in early 2009. The results of this study should enable us to gain a better understanding of the organisational and financial factors that have influenced and will influence the development of services for patients with ESRD around the world.

Acknowledgements: The study group would like to thank the renal registries and national experts around the world who have kindly provided data to the study and the national experts who have agreed to give their opinion as to the organisation of renal services in their country.

The EVEREST study group: Dr Fergus Caskey, Richard Bright Renal Unit, Bristol, UK (Lead Investigator); Professor Adrian Covic, Societatea Romana de Nefrologie and University of Medicine "Gr T Popa"Iasi, Romania; Dr Ana Cusumano, Sociedad Latinoamericana de Nefrologia e Hipertensión, Latin America; Professor Robert Elliott, HERU, University of Aberdeen, UK; Claudia Geue, HERU, University of Aberdeen, UK; Dr Kitty Jager, ERA-EDTA Registry, AMC, Amsterdam, The Netherlands; Anneke Kramer, ERA-EDTA Registry, AMC, Amsterdam, The Netherlands; Professor Alison MacLeod; Department of Medicine and Therapeutics, University of Aberdeen, UK; Dr Benedicte Stengel, Institut National de la Santé de la Recherche Médicale, France; Dr Vianda Stel, ERA-EDTA Registry, AMC, Amsterdam, The Netherlands.

References

1. U.S. Renal Data System: USRDS 2007 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States. Bethesda, MD, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, 2007
2. Caskey FJ, Schober-Halstenberg HJ, Roderick PJ, et al.: Exploring the differences in epidemiology of treated ESRD between Germany and England and Wales. Am J Kidney Dis 47: 445-454, 2006
3. Van Dijk PC, Jager KJ, Stengel B, Gronhagen-Riska C, Feest TG and Briggs JD: Renal replacement therapy for diabetic end-stage renal disease: data from 10 registries in Europe (1991-2000). Kidney international 67: 1489-1499, 2005
4. Hallan SI, Coresh J, Astor BC, et al.: International comparison of the relationship of chronic kidney disease prevalence and ESRD risk. J Am Soc Nephrol 17: 2275-2284, 2006
5. MacGregor MS, Agar JWM and Blagg CR: Home haemodialysis--international trends and variation. Nephrol Dial Transplant 21: 1934-1945, 2006
6. Held PJ, Brunner F, Odaka M, Garcia JR, Port FK and Gaylin DS: Five-year survival for end-stage renal disease patients in the United States, Europe, and Japan, 1982 to 1987. Am J Kidney Dis 15: 451-457, 1990
7. Khan IH, Campbell MK, Cantarovich D, et al.: Survival on renal replacement therapy in Europe: is there a 'centre effect'? Nephrol Dial Transplant 11: 300-307, 1996

From Fergus J Caskey, Kitty Jager, Robert F Elliott, Vianda Stel and Alison M MacLeod for the EVEREST Study group