Population health impacts of dementia among Indigenous Australians

This page presents the latest data showing the population health impacts of dementia among Indigenous Australians including:

Prevalence and incidence of dementia

Although there are no national-level estimates of the number of Indigenous Australians with dementia, studies examining different communities of Indigenous Australians have consistently found that dementia prevalence rates are about 3–5 times as high as rates for Australia overall.

High dementia prevalence (that is, all dementia cases in a given period) and incidence (that is, new dementia cases in a given period) have been documented recently for very different groups of Indigenous Australians:

  • rates of dementia for Indigenous Australians in remote and rural communities are among the highest in the world. For Indigenous Australians aged 45 and over living in the remote Kimberley region of Western Australia, dementia prevalence was 12.4% (Smith et al. 2008), and when followed up 7 years later for those aged 60 and over, dementia incidence was 21 per 1,000 person years (LoGiudice et al. 2016)
  • across the Northern Territory, the age-adjusted prevalence of dementia diagnoses recorded in electronic health data systems for Indigenous Australians aged 45 and over was 6.5%, compared with 2.6% among the non-Indigenous Australians (Li et al. 2014)
  • Indigenous Australians also had a younger age of onset of dementia, with a median age of 72 years compared with a median age of 79 years among non-Indigenous Australians. The age-adjusted incidence rate of dementia among Indigenous Australians aged 45 and over was about 2.5 times as high as the rate among non-Indigenous Australians (27 and 11 per 1,000 person years, respectively) (Li et al. 2014)
  • among urban and regional dwelling Indigenous Australians aged 60 and over, the prevalence of dementia was about 3 times higher than the overall Australian prevalence for the same age group (21% and 6.8%, respectively), with Alzheimer’s disease being the most common type of dementia present. Dementia prevalence rates among urban and regional dwelling Indigenous Australians were slightly lower compared to rates among Indigenous Australians living in remote areas (Radford et al. 2017)
  • A study by Russell et al. (2020), estimated a dementia prevalence of 14.2% among Torres Strait Islanders aged between 45 and 93 years.

Evidence of high prevalence, younger onset, and high incidence of dementia, suggests that without interventions to help moderate the impact of dementia, its burden among Indigenous Australians will continue to grow in coming years.

Preventing dementia in Indigenous Australians requires an understanding of the underlying medical and social risk factors for developing dementia. Some important risk factors that present at higher levels among Indigenous Australians include: head injury, stroke, diabetes, high blood pressure, renal disease, cardiovascular disease, obesity, hearing loss, childhood stress and trauma, and lower socioeconomic status (Flicker & Holdsworth 2014; Radford et al. 2019; Goldberg et al. 2018). A key national research priority is to develop and evaluate culturally responsive programs, interventions and policies to reduce dementia risk factors across the life course and prevent or delay the onset of cognitive decline and dementia (including by targeting social determinants of health) (NHMRC 2020).

Continuing the improvement and quality of Indigenous identifiers in administrative data sets would support better dementia prevalence estimates for Indigenous Australians across Australia (Griffiths et al. 2019; AIHW 2020). Similarly, ensuring the availability and uptake of culturally sensitive and validated assessment tools to diagnose cognitive decline and dementia would lead to improved estimates of dementia prevalence as well as better diagnosis of dementia among Indigenous Australians. The Kimberley Indigenous Cognitive Assessment (KICA) tool is an example of such a tool, which allows for the cognitive screening of older Indigenous Australians living in urban, rural (KICA urban regional) and remote (KICA remote) areas of Australia, as well as the assessment of possible dementia. The complete resource package includes patient and carer assessments, family reports, pictures, and an instruction booklet and video. These are available from Aboriginal Ageing Well Research.

Deaths due to dementia among Indigenous Australians

This section reports on deaths where dementia was recorded as the underlying cause of death, and refers to these as deaths due to dementia. It also presents death statistics aggregated over several years as a result of the small number of deaths due to dementia among Indigenous Australians in any given year. Refer to Deaths due to dementia for more information on dementia-related deaths for all Australians. See the Technical notes for more information about deaths data, such as known issues with under-identification of Indigenous Australians. 

During 2017–19, 314 Indigenous Australians died due to dementia (196 women and 118 men). During this period, dementia was the fifth leading cause of death among Indigenous Australians aged 65 and over (after coronary heart disease, chronic obstructive pulmonary disease, diabetes, and lung cancer), accounting for 7.7% of all deaths among Indigenous Australians aged 65 and over.

To assess trends in deaths due to dementia over the past 10 years, the number of deaths due to dementia for 2010–2014 were compared to the number of deaths in the most recent 5-year period (2015–19). The number of deaths due to dementia among Indigenous Australians increased in the most recent 5-year period (2015–19) for men and women across all ages (Figure 12.1). During 2010–2014, there were 270 deaths due to dementia among Indigenous Australians, while there were 461 deaths due to dementia during 2015–19; this is equivalent to a 71% increase in deaths due to dementia among Indigenous Australians during this period.

Between 2015 and 2019, most deaths due to dementia among Indigenous men and women occurred among those aged 85 and over, but a larger proportion of Indigenous men (67%) were aged less than 85 compared to Indigenous women (54%). With an ageing Indigenous Australian population, it is expected that the number of deaths due to dementia will continue to rise in the future.

Figure 12.1: Deaths due to dementia among Indigenous Australians during 2010–2014 and 2015–2019, by age and sex

Figure 12.1 is a bar graph showing the number of deaths due to dementia among Indigenous Australians during 2010–2014 and 2015–2019 by age and sex. Indigenous Australians aged 85 or older accounted for the largest number of deaths due to dementia for both time periods, but the number of deaths in 2015–19 were greater than in 2010–2014.

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The majority of deaths among Indigenous Australians due to dementia in 2017–19, were recorded as due to Unspecified dementia (219 deaths or 70% of deaths due to dementia), followed by Alzheimer’s disease (17%) and Vascular dementia (9.0%) (Table S12.4). These dementia types were also the most common types recorded overall among Australians who died due to dementia in 2019 (see the Deaths due to dementia).

A recent nationwide study of mortality data between 2006–2014 showed that deaths with dementia were 57% higher among Indigenous Australians compared to non-Indigenous Australians, with the biggest difference occurring among men and those aged less than 75. Indigenous Australians were also more likely to have dementia coded as Unspecified dementia, compared to non-Indigenous Australians (Waller et al. 2021).

Due to the low number of deaths among Indigenous Australians for particular types of dementia, and because there are known limitations with the accuracy and consistency of dementia coding on death certificates, the breakdowns by dementia subtypes presented here can only be considered indicative of the distribution of dementia types among Indigenous Australians. For more information on these limitations, see Deaths due to dementia and Technical notes.

Geographic variation

After accounting for population differences in different geographic areas in Australia, there are notable geographic variations in deaths due to dementia during 2017–19 (Figure 12.2). Age-standardised rates of deaths due to dementia among Indigenous Australians were:

  • lowest in New South Wales (42 per 100,000 Indigenous Australians) and highest in the Northern Territory (116 per 100,000 Indigenous Australians)
  • lowest in Inner and outer regional areas (52 per 100,000 Indigenous Australians) and highest in Remote and very remote areas (119 per 100,000 Indigenous Australians).

Figure 12.2: Deaths due to dementia among Indigenous Australians during 2017—19: age standardised rate by geographic area

Figure 12.2 is a bar graph showing the age standardised rate of deaths due to dementia among Indigenous Australians during 2017–19 by state or territory and remoteness areas. The highest rate was in the Northern Territory with 116 deaths due to dementia per 100,000 Indigenous Australians and lowest in New South Wales (42 deaths per 100,000 Indigenous Australians). Remote and very remote areas had the highest rate of deaths due to dementia among Indigenous Australians (119 deaths per 100,000 Indigenous Australians) and the lowest rate was in Inner and outer regional areas (52 deaths per 100,000 Indigenous Australians).

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Deaths due to dementia versus deaths with dementia

The discussion about dementia deaths among Indigenous Australians has so far been restricted to deaths due to dementia, that is, where dementia was recorded as the underlying cause of death (UCOD). In addition to the underlying cause of death, the National Mortality Database contains information on up to 19 associated causes of death (ACOD)—that is, other causes that were instrumental or significantly contributed to the death. Given people with dementia often have other health conditions and there can only be 1 underlying cause of death recorded, it is important to also account for all other cases where Indigenous Australians died with dementia (where dementia was recorded as the underlying or an associated cause of death).

During 2017–19, 314 Indigenous Australians died due to dementia. In comparison, a total of 618 Indigenous Australians died with dementia (Figure 12.3). Around half (51%) of the deaths with dementia among Indigenous Australians in 2019 were deaths due to dementia (that is, dementia was the underlying cause of death). This proportion increased by age at death, from 43% of deaths with dementia among Indigenous Australians who died aged under 75, to 57% among Indigenous Australians who died aged 85 or over. Across all age groups, the number of deaths involving dementia were much higher when associated cause of death information on dementia was included.

Figure 12.3: Deaths related to dementia among Indigenous Australians during 2017–19, by age

Figure 12.3 is a bar graph showing deaths due to dementia and deaths with dementia among Indigenous Australians during 2017–19 by age. Just over one quarter of all the deaths of Indigenous Australians with dementia were accounted for by those aged less than 75 years during 2017–19. The number of deaths with dementia increased with age to 228 among those aged 85 years or older (or 37% of all deaths of Indigenous Australians with dementia). Overall, deaths due to dementia accounted for about half of the deaths with dementia of Indigenous Australians during this period.

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When dementia was an associated cause of death, common underlying causes of death included: diabetes, coronary heart disease and cerebrovascular disease (Table S12.7). These conditions were also common underlying causes of death among non-Indigenous Australians when dementia was an associated cause of death (Table S3.6). 

Burden of disease

The Indigenous component of the Australian Burden of Disease Study (ABDS) 2011 was the last national study providing estimates of disease burden among Indigenous Australians (AIHW 2016). Burden of disease analysis measures the combined impact of living with illness and injury (non-fatal burden) and dying prematurely (fatal burden). Combined, this is referred to as the total burden, measured using disability-adjusted life years (DALY)—1 DALY is equivalent to 1 year of healthy life lost. Burden of disease allows for comparisons of all diseases, illness and injury, by taking into account not only the number of people affected, but also the severity and duration of illness and age at death for fatal conditions (AIHW 2019).

From the 2011 ABDS, dementia was the leading cause of disease burden for Indigenous women and the third leading cause for Indigenous men aged 75 and over (behind coronary heart disease and chronic obstructive pulmonary disease). The age-standardised rate of disease burden due to dementia was 12.8 DALY per 1,000 Indigenous Australians (or just under 2,900 DALY). This was 2.3 times as high as the burden due to dementia among other Australians (5.7 DALY per 1,000 non-Indigenous Australians).

The AIHW is currently revising the estimates for disease burden in Australia overall and for Indigenous Australians for the year 2018. See Burden of disease due to dementia for the overall dementia burden in Australia in 2018. Estimates for Indigenous Australians are scheduled for release on the AIHW website in late 2021.