Characteristics and outcomes of Aboriginal and Torres Strait Islander patients with dialysis-dependent kidney disease in Australian intensive care units

Background: In Australia, 531 people per million population have dialysis-dependent chronic kidney disease (CKD5D). The incidence is four times higher for Aboriginal and Torres Strait Islander (indigenous) people compared with non-Indigenous Australians. CKD5D increases the risk of hospitalisation, admission to the intensive care unit (ICU) and mortality compared with patients without CKD5D. There is limited literature describing short-term outcomes of patients with CKD5D who are admitted to the ICU, comparing indigenous and non-indigenous patients. Aims: This registry-based retrospective cohort analysis compared demographic and clinical data between indigenous and non-indigenous patients with CKD5D and tested whether indigenous status predicted short-term outcomes independently of other contributing factors. Adjusted hospital mortality was the primary outcome measure. Methods: Data were from the Australian and New Zealand Intensive Care Society's Centre for Outcome and Resource Evaluation Adult Patient Database. Australian ICU admissions between 2010 and 2017 were included. Data from 173 ICU (2136 beds) include 1 051 697 ICU admissions, of which 23 793 had a pre-existing diagnosis of CKD5D. Results: Indigenous patients comprised 11.9% of CKD5D patients in ICU. CKD5D was prevalent among 4.9% of indigenous and 2.9% of non-indigenous ICU admissions. Indigenous patients were 13.5 years younger, had fewer comorbidities and lower crude mortality despite equivalent calculated mortality risk. After adjusting for age, remoteness and severity of illness, indigenous status did not predict mortality. Conclusions: Socioeconomic disadvantage contributes to earlier development of CKD5D and the overrepresentation in ICU of indigenous people. Mortality is equivalent once correcting for confounders, but addressing inequality requires strengthening preventative care.