Increases in renal replacement therapy in Australia and New Zealand: Understanding trends in diabetic nephropathy

Aim: The incidence of end-stage kidney disease (ESKD) has been increasing worldwide, with increasing numbers of older people, people with diabetic nephropathy and indigenous people. We investigated the incidence of renal replacement therapy (RRT) in Australia and New Zealand (NZ) to better understand the causes of these effects. Methods: Data from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) registry and relevant population data were used to investigate the incidence of RRT in five demographic groups: Indigenous and non-indigenous Australians, Maori, Pacific Islanders and other New Zealanders, as well as differences between genders and age groups. Results: The numbers of patients commencing RRT each year increased by 321% between 1990 and 2009. This increase was largely driven by increases in patients with diabetic nephropathy. In 2009 35% of new patients had ESKD resulting from diabetic nephropathy 92% of which were type 2. Indigenous Australians, and Maori and Pacific people of NZ have elevated risks of commencing RRT due to diabetic nephropathy, although the risks compared with non-indigenous Australians have decreased over time. A small element of lead time bias also contributed to this increase. Males are more likely to commence RRT due to diabetes than females, except among Australian Aborigines, where females are more at risk. There is a marked increase in older, more comorbid patients. Conclusions: Patterns of incident renal replacement therapy strongly reflect the prevalence of diabetes within these groups. In addition, other factors such as reduced risk of dying before reaching ESKD, and increased acceptance of older and sicker patients are also contributing to increases in incidence of RRT.