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Santos et al. Vessel Plus 2021;5:21 https://dx.doi.org/10.20517/2574-1209.2020.69 Page 3 of 16

METHODS
Using narrative review methods we searched PubMed and performed manual searches of references from
[13]
retrieved literature. Our PICO model was defined as: P: Indigenous Peoples, I: Stroke, C: Non-Indigenous
Peoples, O: Incidence or prevalence, risk factors and treatment. Our Indigenous search terms were extensive
and comprehensive in order to include all possible Indigenous groups worldwide. Papers were only
included if they comprehensively assessed either incidence or prevalence, cardiovascular risk factors, or
treatment of stroke in the Indigenous population of the specific region and made reference to the non-
Indigenous Peoples in the same region.

RESULTS
Incidence of stroke in Indigenous Peoples
Indigenous populations typically experience greater rates of stroke incidence compared with the non-
Indigenous population in the same region [11,14,15] . The reasons for this are multifactorial and differ between
the different populations; however, many Indigenous populations share common health and socioeconomic
[3,4]
disadvantages as described above . Relatively few comparative data for certain regions have been
published. There are many reasons for this, including that some Indigenous groups have expressed the wish
not to be compared in this way to other population groups.

In Australia, the age-standardised incidence rate of stroke in Aboriginal and Torres Strait Islander
(Indigenous) Australians has been reported to be significantly greater than that in the non-Indigenous
population [11,14-16] , with even greater disparities at younger ages . In one study, comprising prospectively
[11]
ascertained data, the incidence of all stroke subtypes in the Indigenous Australian population of South
Australia aged < 55 years was 3.5-fold that of the non-Indigenous population . In this study, the rate of
[11]
ICH was especially high in this younger population, 16-fold greater than that in the non-Indigenous
population of the same age . In Aotearoa (New Zealand), the Māori population have experienced
[11]
improvements in stroke incidence over the past three decades. However, these improvements have been of a
[17]
lesser magnitude than New Zealanders of European descent . In the Pacific Islands, stroke is one of the
leading causes of death and disability; however, precise measurements of incidence in these regions are
[18]
sparse .
In Asia, few studies have specifically been undertaken to investigate the incidence of stroke in Indigenous
Peoples. In one study, the age-standardised incidence rate of stroke in Lhasa, Tibet, was less in Indigenous
[19]
Tibetan people than that in Han Chinese people . However, in those with incident stroke, Tibetan patients
had a greater proportion of ICH (47.9%) than Han Chinese patients (29.5%) . Similarly, few data are
[19]
available on the incidence of stroke in Indigenous Peoples of the Middle East. In one retrospective cohort
study, the Ramadan month of fasting was associated with a significantly increased rate of hospitalisation for
incident IS among the Indigenous Bedouin Arab people in southern Israel, when compared with the rest of
the year, and when compared with non-Bedouin people during the month of Ramadan . Furthermore,
[20]
during the full (Ramadan and non-Ramadan) study period, Bedouin patients with incident IS were younger
[20]
than non-Bedouin patients (66.9 years vs. 73.1 years, P < 0.001) . In our search, we were unable to identify
any peer-reviewed literature describing the incidence of stroke in Indigenous minorities of Africa.

In a single study in the Americas (excluding Hawaii), there was a greater incidence of stroke in American
Indians and Alaska Natives than in White and Black Americans [21,22] . Overall, there were similar proportions
of ischaemic and haemorrhagic stroke subtypes between these different groups. However, in younger age
groups, there was a greater proportion of haemorrhagic stroke in American Indians . Muller et al.
[23]
[21]
recently pooled data from two cohort studies, and showed that the age-standardised incidence of stroke in