What are my chances, doc? The competing risks of death and transplantation for Indigenous Australian dialysis patients

Aim: To examine the chances of death and transplantation for Indigenous and non-Indigenous young and middle-aged adult Australian dialysis patients.

Background: Transplant rates are lower and the risk of death higher for Indigenous compared to non-Indigenous patients. Previous analyses have not used competing risks methods over time for dialysis patients by remoteness.

Methods: Using ANZDATA registry data, all patients in Australia commencing dialysis aged 15–64 years from 1st April 1995 to 31st December 2009 were included and followed for five years, until 31st December 2012. The unadjusted cumulative incidence of death and transplantation was estimated for Indigenous and nonIndigenous patients and the weighted area between functions compared. Fine and Gray competing risks proportional hazards (CR-PH) models adjusted for age, sex, late referral, comorbidities, cohort and remoteness category were calculated for the five-year risk of death and transplantation.

Results: 89.3% of all adult Indigenous but only 52.3% of all adult nonIndigenous dialysis patients were included; included Indigenous patients had more comorbidities than non-Indigenous patients. Unadjusted analysis showed significant differences between Indigenous and non-Indigenous patients in both risk of death (p < 0.001) and transplantation (p < 0.001). The adjusted CR-PH model for death showed the Indigenous : non-Indigenous gap narrowed: sub-hazard ratios (SHR, with 95%CIs) for major capital cities (MC) 1995–1999 SHR 1.43 (1.13–1.82) to 2005–2009 SHR 1.21 (0.97–1.52). For transplantation, the adjusted CR-PH model showed a widening gap in MC over time: 1995–1999 SHR 0.49 (0.34–0.70) to 2005–2009 SHR 0.30 (0.20– 0.46). Transplantation increased by remoteness for non-Indigenous patients, with an opposite pattern for Indigenous patients.

Conclusions: Survival differences between Indigenous and non-Indigenous dialysis patients have improved over time. Indigenous transplant rates have worsened. Urgent attention is needed to ensure equitable outcomes.