Stroke Epidemiology in Oceania: A Review

Abstract

Background and purpose: Oceania, comprising the regions Australasia, Melanesia, Micronesia, and Polynesia, is home to 42 million living in 8.5 million square kilometres of land. This paper comprises a review of the epidemiology of stroke in countries in this region.

Methods: Information on epidemiology of stroke in Oceania was sought from data from the Global Burden of Disease (GBD) study (incidence, mortality, incidence:mortality ratio [IMR], prevalence, disability-adjusted life-years [DALYs] lost due to stroke, and subtypes), World Health Organization (WHO) (vascular risk factors in the community), and PubMed (incidence, prevalence, and stroke subtypes). Data were analyzed by region to allow inter-country comparison within each region.

Results: In 2010, age- and sex-standardized stroke mortality rates were lowest in Australasia (29.85-31.67/100,000) and highest in Melanesia and Micronesia (56.04-187.56/100,000), with wide ranges especially in Melanesia. Incidence rates were lowest in Australasia (101.36-105.54/100,000), similarly high elsewhere. Standardized IMR (0.98-3.39) was the inverse of the mortality rates and mirrored the prevalence rates (202.91-522.29/100,000). DALY rates (398.22-3,781.78/100,0000) mirrored the mortality rates. Stroke risk factors show a variable pattern - hypertension is generally the most common medical risk factor among males (18.0-26.6%), while among females, diabetes mellitus is the most common in Micronesia and Polynesia (21.5-28.4%). Among the lifestyle factors, current smoking is the most common in Melanesia among males, while obesity is generally the most common factor among females. Ischaemic stroke comprises 70% of stroke subtypes. Trend data show significant falls in standardized mortality rates and DALYs in most regions and falls in incidence in almost all countries. There is significant economic impact, particularly due to young strokes; some ethnicities are at higher risk than others, for example, Maoris and Pacific Islanders.

Conclusions: Stroke is a major healthcare problem in Oceania. Variations in stroke epidemiology are found between countries in Oceania. Data are lacking in some; more research into the burden of stroke in Oceania is needed. With the expected increase in life expectancy and vascular risk factors, the burden of stroke in Oceania will likely rise. Some of the disparities in stroke burden may be addressed by great investment in healthcare.

Keywords: Burden; Epidemiology; Oceania; Stroke.