Black ethnicity predicts better survival on dialysis despite greater deprivation and co- morbidity: a UK study

Background: Observational studies from the United States have identified black race as conferring a survival advantage on dialysis. This study represents the first large single-center study from a UK dialysis unit examining the outcome of ethnic minorities on renal replacement therapy (RRT). Methods: A retrospective analysis of all patients of white or black race initiating RRT at King’s College Hospital Renal Unit, London, between 1996 and 2008 was performed. A total of 1,340 patients were studied, of which 952 (71%) were of white race, and 388 (29%) were of black race. Kaplan-Meier survival curves, the log rank test and Cox’s proportional hazard models were used to compare survival between groups. Results: The results revealed black ethnicity to be associated with a significant survival benefit on dialysis. This was the case even after adjustment for age, gender, diabetes, transplantation, and deprivation. In those patients not transplanted, black race conferred a hazard ratio (HR) of 0.51 (95% CI 0.41 – 0.63) over 5 years. Conclusions: This study provides evidence for a lower mortality rate amongst black patients on dialysis in comparison with their white counterparts in the UK. The reasons behind this remain poorly understood but a lower incidence of cardiovascular disease in black patients and more kidney-limited disease may be important.