Dialysis outcomes of elderly Indigenous and non-Indigenous Australians.

Abstract

Whilst increasing numbers of elderly people in Australia are commencing dialysis, few Indigenous patients are aged ≥ 65 years and their outcomes are unknown. We compared the long-term survival, mortality hazards and causes of death between elderly Indigenous and elderly non-Indigenous dialysis patients. This was a retrospective cohort study of adults aged ≥ 65 years who commenced dialysis in Australia from 2001-2011, identified from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Indigenous (n = 263) and non-Indigenous (n = 10,713) patients were followed until death, loss to follow-up, recovery of renal function or 31 December 2011. Mortality was compared using a multivariate Cox proportional-hazards model with age, gender, body mass index, smoking, primary renal disease, comorbidities, late referral and initial treatment modality as predictive variables. Median follow-up was 26.9 months (interquartile range 11.3-48.8 months). Overall 166 Indigenous and 6265 non-Indigenous patients died during the 11-year follow-up period. Mortality rates per 100 patient-years were 23.9 for Indigenous patients and 21.2 for non-Indigenous patients. The overall 1-, 3- and 5-year survival rates were 81%, 49% and 27% for Indigenous patients and 82%, 55% and 35% for non-Indigenous patients respectively. Indigenous patients had a 20% increased risk of mortality compared with non-Indigenous patients (adjusted hazard ratio 1.20, 95% confidence interval, 1.02, 1.41; P = 0.02). 'Social deaths' (predominantly dialysis withdrawal) and cardiac deaths were the main causes of death for both groups. Among elderly dialysis patients in Australia, Indigenous status remains an important factor in predicting survival.