Estimating the total incidence of kidney failure in Australia including individuals who are not treated by dialysis or transplantation.

BACKGROUND: To date, incidence data for kidney failure in Australia have been available for only those who start renal replacement therapy (RRT). Information about the total incidence of kidney failure, including non-RRT-treated cases, is important to help understand the burden of kidney failure in the community and the characteristics of patients who die without receiving treatment. STUDY DESIGN: Data linkage study of national observational data sets. SETTING & PARTICIPANTS: All incident treated cases recorded in the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) probabilistically linked to incident untreated kidney failure cases derived from national death registration data for 2003-2007. PREDICTOR: Age, sex, and year. OUTCOMES: Kidney failure, a combination of incident RRT or death attributed to kidney failure (without RRT). MEASUREMENTS: Total incidence of kidney failure (treated and untreated) and treatment rates. RESULTS: There were 21,370 incident cases of kidney failure in 2003-2007. The incidence rate was 20.9/100,000 population (95% CI, 18.3-24.0) and was significantly higher among older people and males (26.1/100,000 population; 95% CI, 22.5-30.0) compared with females (17.0/100,000 population; 95% CI, 14.9-19.2). There were similars number of treated (10,949) and untreated (10,421) cases, but treatment rates were influenced highly by age. More than 90% of cases in all age groups between 5 and 60 years were treated, but this percentage decreased sharply for older people; only 4% of cases in persons 85 years or older were treated (ORs for no treatment of 115 [95% CI, 118-204] for men ≥80 years and 400 [95% CI, 301-531] for women ≥80 years compared with women who were <50 years). LIMITATIONS: Cross-sectional design, reliance on accurate coding of kidney failure in death registration data. CONCLUSIONS: Almost all Australians who develop kidney failure at younger than 60 years receive RRT, but treatment rates decrease substantially above that age.