Factors Associated with the High Prevalence of Dementia in Older Aboriginal Australians

Abstract

Dementia prevalence in Aboriginal and Torres Strait Islander Australians is three to five times higher than the general Australian population. A better understanding of the underlying biomedical and social risk factors is needed to guide dementia prevention in Aboriginal Australians. The current study is the first to examine potential risk factors for dementia in the majority urban and regional population, with a representative sample of 336 Aboriginal Australians aged 60 years and older. Participants included 45 people with a dementia diagnosis ( n = 27 probable/possible Alzheimer’s disease); and 286 people without dementia. Univariate logistic regression analyses (controlling for age) identified childhood trauma, mid-life factors (history of unskilled work, past high-risk alcohol use), and medical factors (history of stroke, head injury with loss of consciousness, epilepsy) as risk factors for dementia. Multivariable analysis revealed age, childhood trauma, unskilled work, stroke, and head injury as independent predictors of all-cause dementia. A range of comorbid factors related to dementia was also identified (i.e., functional impairment, incontinence, recent hospital admission, low body mass index, living in residential care, depression, current high-risk alcohol use, social isolation, low physical activity levels). These findings extend previous outcomes in a remote Aboriginal population by highlighting that life-course social determinants of health, in addition to neurological disorders, likely play an important role in elevating dementia risk. Certain psychosocial and medical exposures are highly prevalent in Aboriginal Australians, similar to other indigenous populations, and should be considered when designing targeted and culturally appropriate prevention initiatives to reduce the burden of dementia.

Using Cross-Cultural Studies to Improve Evidence on Dementia Prevention: Lessons from the Special Issue Sponsored by the International Research Network on Dementia Prevention (IRNDP)

“…Radford et al's study [19] of factors associated with dementia in a sample of 336 Aboriginal Australians aged 60+ years illustrates both the promise and challenges of focusing research attention in communities rarely represented in dementia studies. Previous work indicates Aboriginal Australians have substantially higher dementia risk than other Australians [20], and although the existing evidence base is limited, this demonstrates the relevance of ADRD for Aboriginal health.…”

“…Previous work indicates Aboriginal Australians have substantially higher dementia risk than other Australians [20], and although the existing evidence base is limited, this demonstrates the relevance of ADRD for Aboriginal health. Radford et al [19] identified social (childhood trauma and low-skill occupation), behavioral (past high-risk alcohol use) and medical conditions (stroke, head injury) as significant predictors of prevalent dementia. These results are not surprising and indicate general consistency with dementia predictors in other studies, although Radford et al [19] note that education in this sample was not independently associated with dementia.…”

“…Radford et al [19] identified social (childhood trauma and low-skill occupation), behavioral (past high-risk alcohol use) and medical conditions (stroke, head injury) as significant predictors of prevalent dementia. These results are not surprising and indicate general consistency with dementia predictors in other studies, although Radford et al [19] note that education in this sample was not independently associated with dementia. More specifically, the association between education and dementia was not statistically significant, although the effect estimate (OR = 0.82) reported by Radford was protective similar to estimates reported elsewhere, but not precisely estimated.…”

Let’s CHAT (community health approaches to) dementia in Aboriginal and Torres Strait Islander communities: protocol for a stepped wedge cluster randomised controlled trial

“…There is increasing evidence that prevention and management of vascular and other risk factors could delay progression of dementia [9], and this may be of particular relevance in Aboriginal and Torres Strait Islander communities where there are high rates of co-morbid conditions [10,11] and onset at earlier ages, including past head injurya key risk factor associated with decline from normal cognition to impairment [4], and other associations including age, stroke, non-aspirin analgesics, lower BMI, and higher systolic blood pressure (BP) [4]. In addition childhood trauma was found to be a contributor to cognitive decline in urban regions [6,12].…”

Dementia, Risk, Risk Reduction, and Translation into Practice: An International Research Network for Dementia Prevention (IRNDP) Special Issue

“…In a comprehensive umbrella review of systematic reviews, Anstey and colleagues summate the observational evidence on risk factors for Alzheimer's disease, vascular dementia, and any dementia, and highlight the lack of evidence for many risk factor exposures in midlife, a lack of data on risk factors for vascular dementia and from low and middle income countries [15]. The editorial from Glymour and Whitmer takes this further highlighting the need for a life-course understanding, and the importance of risk factor prevalence or saturation in particular populations or those with relatively small numbers (for example indigenous Australian populations) [14,16]. Glymour and Whitmer also helpfully suggest new ways in which we can start to conceptualize, examine, and combine our data to gain the greater understanding we need for future risk reduction [14].…”