Epidemiology and Quality of Care for Aboriginal and Torres Strait Islander Peoples Treated by Emergency Medical Services for Stroke in Victoria, Australia: Retrospective Analysis of Linked Data

OBJECTIVES: To examine the epidemiology of stroke and transient ischaemic attack (TIA), and quality of care provided to Aboriginal and Torres Strait Islander ('Indigenous') patients presenting to emergency medical services (EMSs) with stroke or TIA. DESIGN: Retrospective population-based data linkage study. SETTING, PARTICIPANTS: Victoria, Australia. Patients aged ≥ 18 years with hospital-confirmed stroke or TIA who presented to EMSs between 1 January 2015 and 30 June 2019 and were successfully linked with hospital or mortality datasets. MAIN OUTCOME MEASURES: Thirty- and 90-day mortality, crude and age-standardised incidence rates, EMS quality of care. RESULTS: Among 32,163 patients, 287 (0.9%) were Indigenous. Indigenous patients were younger than non-Indigenous patients (median age, 62 vs. 77 years, p < 0.001). Age-standardised incidence of EMS attendance was higher within the Indigenous population (343 vs. 144 per 100,000 person-years; incidence rate ratio, 2.383 [95% confidence interval (CI), 2.084-2.711]). Rates of call-taker identification of stroke or TIA and hospital diagnoses were comparable; however, Indigenous patients were less likely to receive a stroke assessment from paramedics (166/285 [58.2%] vs. 21,271/31,605 [67.3%]; p = 0.001) and more frequently taken to stroke-capable hospitals (257/275 [93.5%] vs. 27,371/30,647 [89.3%]; p = 0.027), but less frequently taken to endovascular thrombectomy-capable hospitals (67/275 [24.4%] vs. 10,015/30,647 [32.7%]; p = 0.003). Adjusted mortality was similar between groups (30 days: hazard ratio, 0.814 [95% CI, 0.518-1.279]; 90 days: hazard ratio, 0.805 [95% CI, 0.534-1.214]). However, age-standardised incidence of 90-day mortality was higher within the Indigenous population (39 vs. 24 per 100,000 person-years; incidence rate ratio, 1.621 [95% CI, 1.031-2.398]). Indigenous patients also more often recontacted EMSs for any reason within 90 days (subdistribution hazard ratio, 1.548 [95% CI, 1.194-2.007]). CONCLUSIONS: The age-standardised incidence of EMS attendance for stroke in the Indigenous population was more than double that for the non-Indigenous population. Although there was no difference in stroke identification at the time of the emergency call, Indigenous patients were less likely to be evaluated by paramedics for stroke.