Long term outcomes for Aboriginal and Torres Strait Islander Australians after hospital intensive care

Objectives: To assess long term outcomes for Aboriginal and Torres Strait Islander (Indigenous) Australians admitted non-electively to intensive care units (ICUs). Design: Data linkage cohort study; analysis of ICU patient data (Australian and New Zealand Intensive Care Society Adult Patient Database), prospectively collected during 2007–2016. Setting: All four university-affiliated level 3 ICUs in South Australia. Main outcomes: Mortality (in-hospital, and 12 months and 8 years after admission to ICU), by Indigenous status. Results: 2035 of 39 784 non-elective index ICU admissions (5.1%) were of Indigenous Australians, including 1461 of 37 661 patients with South Australian residential postcodes. The median age of Indigenous patients (45 years; IQR, 34–57 years) was lower than for non-Indigenous ICU patients (64 years; IQR, 47–76 years). For patients with South Australian postcodes, unadjusted mortality at discharge and 12 months and 8 years after admission was lower for Indigenous patients; after adjusting for age, sex, diabetes, severity of illness, and diagnostic group, mortality was similar for both groups at discharge (adjusted odds ratio [aOR], 0.95; 95% CI, 0.81–1.10), but greater for Indigenous patients at 12 months (aOR, 1.14; 95% CI, 1.03–1.26) and 8 years (adjusted hazard ratio, 1.23; 95% CI, 1.13–1.35). The number of potential years of life lost was greater for Indigenous patients (median, 24.0; IQR, 15.8–31.8 v 12.5; IQR, 0–22.3), but, referenced to respective population life expectancies, relative survival at 8 years was similar (proportions: Indigenous, 0.78; 95% CI, 0.75–0.80; non-Indigenous, 0.77; 95% CI, 0.76–0.78). Conclusions: Adjusted long term mortality and median number of potential life years lost are higher for Indigenous than non-Indigenous patients after intensive care in hospital. These differences reflect underlying population survival patterns rather than the effects of ICU admission.