Stroke incidence and subtypes in Aboriginal people in remote Australia: a healthcare network population-based study
Anna Balabanski, Kendall Goldsmith, Blake F. Giarola, David Buxton, Sally Castle, Katharine McBride, Stephen Brady, Amanda G. Thrift, Judith Katzenellenbogen, Alex Brown, James N. Burrow, Geoffrey A. Donnan, Simon A. Koblar, Timothy Kleinig
Abstract
OBJECTIVES: We aimed to compare the incidence, subtypes and aetiology of stroke, and in-hospital death due to stroke, between Aboriginal and non-Aboriginal people in Central Australia, a remote region of Australia where a high proportion Aboriginal people reside (40% of the population). We hypothesised that the rates of stroke, particularly in younger adults, would be greater in the Aboriginal population, compared with the non-Aboriginal population; we aimed to elucidate causes for any identified disparities. DESIGN: A retrospective population-based study of patients hospitalised with stroke within a defined region from 1 January 2011 to 31 December 2014. SETTING: . PARTICIPANTS: 161 residents (63.4% Aboriginal) of the catchment area admitted to hospital with stroke. PRIMARY AND SECONDARY OUTCOME MEASURES: Rates of first-ever stroke, overall (all events) stroke and in-hospital death. RESULTS: Of 121 residents with first-ever stroke, 61% identified as Aboriginal. Median onset-age (54 years) was 17 years younger in Aboriginal patients (p<0.001), and age-standardised stroke incidence was threefold that of non-Aboriginal patients (153 vs 51 per 100 000, incidence rate ratio 3.0, 95% CI 2 to 4). The rate ratios for the overall rate of stroke (first-ever and recurrent) were similar. In Aboriginal patients aged <55 years, the incidence of ischaemic stroke was 14-fold greater (95% CI 4 to 45), and intracerebral haemorrhage 19-fold greater (95% CI 3 to 142) than in non-Aboriginal patients. Crude prevalence of diabetes mellitus (70.3% vs 34.0%, p<0.001) and hypercholesterolaemia (68.9% vs 51.1%, p=0.049) was greater, and age-standardised in-hospital deaths were fivefold greater (35 vs 7 per 100 000, 95% CI 2 to 11) in Aboriginal patients than in non-Aboriginal patients. CONCLUSIONS: Stroke incidence (both subtypes) and in-hospital deaths for remote Aboriginal Australians are dramatically greater than in non-Aboriginal people, especially in patients aged <55 years.