Dementia in Australia

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

• prevalence and incidence of dementia
• deaths due to dementia 
• deaths due to dementia versus deaths with dementia.

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.
• The ARC Centre for Excellence in Population Ageing Research projected that by 2051, the relative growth in the number of Indigenous Australians aged 50 years and over with dementia will be 4.5 to 5.5 times the 2016 estimated prevalence (Temple et al. 2022). The study attributes this to the Aboriginal and Torres Strait Islander population ageing, where age is a known risk factor for dementia. 

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 and Holdsworth 2014; Goldberg et al. 2018; Radford et al. 2019). 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 (AIHW 2020; Griffiths et al. 2019). 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 2018–20, 318 Indigenous Australians died due to dementia (202 women and 116 men). During this period, dementia was the fifth leading cause of death among Indigenous Australians aged 65 and over (298 deaths, after coronary heart disease, chronic obstructive pulmonary disease, diabetes, and lung cancer), accounting for 11% 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 2011–2015 were compared to the number of deaths in the most recent 5-year period (2016–20). The number of deaths due to dementia among Indigenous Australians increased in the most recent 5-year period (2016–20) for men and women across all ages (Figure 12.1). During 2011–2015, there were 296 deaths due to dementia among Indigenous Australians, while there were 503 deaths due to dementia during 2016–2020; this is equivalent to a 70% increase in deaths due to dementia among Indigenous Australians during this period.

Between 2016 and 2020, most deaths due to dementia among Indigenous men and women occurred among those aged 85 and over, but a larger proportion of Indigenous men (71%) were aged less than 85 compared to Indigenous women (52%). 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 2011–2015 and 2016–2020, by age and sex

The majority of deaths among Indigenous Australians due to dementia in 2018–20, were recorded as due to Unspecified dementia (215 or 68% of deaths due to dementia), followed by Alzheimer’s disease (19%) and Vascular dementia (10%) (Table S12.4). These dementia types were also the most common types recorded overall among Australians who died due to dementia in 2020 (see the Deaths due to dementia).

A 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 years. 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 2018–20 (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 (115 per 100,000 Indigenous Australians)
• lowest in Inner and Outer regional areas (49 per 100,000 Indigenous Australians) and highest in Remote and Very remote areas (117 per 100,000 Indigenous Australians).

Figure 12.2: Deaths due to dementia among Indigenous Australians during 2018–20: age standardised rate by geographic area

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. In addition to the underlying cause of death, the National Mortality Database contains information on up to 19 associated causes of death – 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 either the underlying cause or an associated cause of death).

During 2018–20, around half of all deaths with dementia among Indigenous Australians were deaths due to dementia (318 deaths out of 646). This proportion increased by age at death, from 41% of deaths with dementia among Indigenous Australians who died aged under 75, to 53% 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 2018–20, by age

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 Australians generally when dementia was an associated cause of death (Table S3.6).