The incidence of stroke in the Aboriginal and non-Aboriginal populations of Western Australia, South Australia and the Northern Territory (2012-2015).

Abstract

Background: Most estimates of stroke incidence among Aboriginal and Torres Strait Islander (hereinafter respectfully referred to as Aboriginal) Australians include limited case numbers and are generally confined to single regions. Aim(s): To measure age-standardised stroke incidence in Aboriginal and non-Aboriginal Australians in Western Australia (WA), South Australia (SA) and the Northern Territory (NT) combined. Method(s): We used whole-population multi-jurisdictional person-linked data from hospital and death datasets to identify stroke admissions and stroke-related deaths (2001-2015). We utilised hospital, emergency department and death datasets to identify Aboriginal people. We identified incident (firstever) strokes in patients aged 20-84 during the study period (2012-2015), using a 10-year lookback period to exclude previous stroke events. Incidence rates for the Aboriginal and non-Aboriginal population per 100,000/year were estimated, age-standardised to the world population aged 20-84. Result(s): We identified 17,986 incident strokes (32.2% fatal) between 2012-2015. Of these, 752 (4.2%) occurred in Aboriginal people (23.1% fatal). Median age at onset (55 years) in Aboriginal people was 16 years younger than non-Aboriginal people (p<0.001). In those aged 20-84 years, the age-standardised stroke incidence was 2.9-fold greater in the Aboriginal population (206/100,000) than the non- Aboriginal population (70/100,000). Disparities were particularly apparent at younger ages (20-54 years), where the age-standardised stroke incidence was 4.4-fold greater in the Aboriginal population (93/100,000) than the non-Aboriginal population (21/100,000). Conclusion(s): In the largest multi-jurisdictional person-linked dataset to date we found significant disparities in stroke incidence between Aboriginal and non-Aboriginal populations, particularly at younger ages. These results will be used to inform region-specific, culturally safe interventions.