What can we learn about dementia from research in Indigenous populations?

Abstract

Indigenous peoples represent up to 5% of the world's population (almost 400 million people), representing thousands of individual cultures and language groups. The health status of older Indigenous peoples has been little researched, partly related to lower life expectancy and the consideration that Indigenous peoples do not live long enough to experience the common “geriatric syndromes” such as dementia, frailty, and falls. Statistics from Australia and Canada now report that Indigenous populations are undergoing rapid aging, with many examples of survivorship to old age (Arkleset al., 2010; Jacklinet al., 2012). The systematic review by Warrenet al. (2015) is a timely one, in that it reminds clinicians interested in old age that this “fourth” World population deserves further attention. Researchers that have worked with these groups to produce population estimates are relatively few. In their systematic review, Warrenet al.(2015) demonstrate wide variation in prevalence rates of dementia. They conclude that a major cause of this heterogeneity in prevalence is due to basic methodological differences. In particular, those studies that have utilized already acquired routine data may be biased. The type and direction of this bias can be complex. For example, Cotteret al.(2012) using routinely collected data, concluded that the prevalence of dementia in Aboriginal Australians in the Northern Territory was not higher than non-Aboriginal prevalence. Using similar methodologies some years later the conclusion was that the Aboriginal population had markedly higher rates (Liet al., 2014). In the intervening period, a dementia awareness campaign coupled with the development of a culturally appropriate screening tool probably resulted in greater detection in routine care.