First stroke incidence, causes, treatments, and outcomes for Aboriginal Peoples in South Australia and the Northern Territory: a pilot prospective study

Objective: We performed a pilot stroke incidence study, focused on feasibility and inclusion of the CONSIDER reporting guidelines, to model the design of a future population-based study aiming to definitively determine stroke incidence, antecedents, treatment, and outcomes. Study design: Prospective stroke incidence study (pilot study). Setting, participants: All people aged 15 years or older who lived in postcode-defined areas of South Australia and Northern Territory (885 472 people, including 45 127 Aboriginal people [5.1%]) diagnosed with stroke for the first time during 1 October – 31 December 2015 and admitted to public hospitals or stroke and transient ischaemic attack clinics. Main outcome measures: Feasibility of a prospective population-based stroke incidence study. Results: Of the 123 participants with first strokes, ten were Aboriginal (8%); the median age of Aboriginal people was 45 years (interquartile range [IQR], 33–55 years), of non-Indigenous people 73 years (IQR, 62–84 years). For Aboriginal people, the age-standardised incidence of stroke was 104 (95% confidence interval [CI], 84–124) per 100 000 person-years, for non-Indigenous people 33 (95% CI, 22–44) per 100 000 person-years. We found that a prospective population-based stroke incidence study in Aboriginal people was feasible, including with respect to establishing an adequate sample size, diagnostic confirmation, identification of incident stroke, confirming stroke subtypes, establishing a stable statistical population, standardising data reporting for comparison with other stroke incidence studies, and ethical research reporting that conforms to CONSIDER guidelines. Conclusions: A larger, population-based study of the incidence of stroke in Aboriginal people is both feasible and needed to provide robust estimates of stroke incidence, antecedents, treatments and outcomes to help guide strategies for reducing the risk of and outcomes of stroke in Aboriginal people.