Dementia in Australia

The Australian Burden of Disease Study (ABDS) 2022 provides projected estimates of burden of disease for 220 diseases and injuries for the total population for 2022. The study used trend analysis techniques to project increases in sex- and age-specific rates in disease burden. Full analysis techniques can be found in the ABDS technical notes.

The Australian Burden of Disease Study (ABDS) 2018 provides Australian-specific burden of disease estimates for the total population for 2018, 2015, 2011 and 2003 and for the Indigenous Australian population for 2018, 2011 and 2003, as well as estimates of the disease burden attributable to specific risk factors. The study utilised and adapted methods developed as part of the previous ABDS 2015 and 2011 (AIHW 2019; AIHW 2016). The ABDS uses Australian data sources and adapts the methods from global studies to produce estimates that are relevant to the Australian context (AIHW 2016).

The fatal burden estimates for dementia were derived from the AIHW National Mortality Database and are considered to be of high quality. National non-fatal burden estimates for dementia were based on prevalence rates published in this online report applied to the relevant Australian estimated resident populations. The severity distribution was based on estimates published by Barendregt and Bonneux (1998) for those aged under 80 and from a study by Lucca et al. (2015) for those aged 80 and over. The quality of the non-fatal burden estimates could be improved if more recent and more generalisable data on dementia prevalence and severity in Australia becomes available. 

A comparative risk assessment method was used to quantify the impact of each risk factor on the disease burden for associated diseases, referred to as the ‘attributable burden’. Diseases that were found to have a causal association with dementia and their associated relative risks (the amount of additional risk of developing dementia if exposed to the risk factor) were based on those used in recent Global Burden of Disease studies and a number of epidemiological studies. The prevalence of exposure to each risk factor was derived from a variety of Australian-specific data sources.

References

AIHW (Australian Institute of Health and Welfare) (2016). Australian Burden of Disease Study: impact and causes of illness and death in Aboriginal and Torres Strait Islander people 2011, catalogue number BOD 7, AIHW, Australian Government, accessed 12 December 2022.

AIHW (2019) Australian Burden of Disease Study: methods and supplementary material 2015, catalogue number BOD 23, AIHW, Australian Government, accessed 15 December 2022.

AIHW (2022) Australian burden of disease study 2022: technical notes, AIHW, Australian Government, accessed 20 December 2022.

Barendregt JJM and Bonneux LGA (1998) Degenerative disease in an ageing population models and conjecture, Erasmus University, Rotterdam.

Lucca U, Tettamanti  M, Logroscino G, Tiraboschi P, Landi C, Sacco L, Garrì M, Ammesso S, Bertinotti C, Biotti A, Gargantini E, Piedicorcia A, Nobili A, Pasina L, Franchi C, Djignefa Djade C, Riva E and Recchia A (2015) ‘Prevalence of dementia in the oldest old: the Monzino 80-plus population based study’, Alzheimer's & dementia, 11(3):258-70.e3, doi:10.1016/j.jalz.2014.05.1750.

The Estimated Resident Population (ERP) is the official measure of the Australian population and contains estimates of the usual resident population of Australia. The ERP includes all people, regardless of nationality or citizenship, who usually live in Australia (except for foreign diplomatic personnel and their families).

Throughout this report, ERP data were used to derive rates of, for example, dementia prevalence and mortality in the Australian population. The ERP data were sourced from the ABS using the most up-to-date estimates available at the time of analysis.

To derive its estimates of the resident populations, the ABS uses the 5-yearly Census of Population and Housing data and adjusts them as described here:

• All respondents in the Census are placed in their state or territory, Statistical Local Area and postcode of usual residence; overseas visitors are excluded.
• An adjustment is made for persons missed in the Census.
• Australians temporarily overseas on Census night are added to the usual residence Census count.

Estimated resident populations are then updated each year from the Census data, using indicators of population change, such as births, deaths and net migration.

Projections of the Australian population past 2020 are formulated on the basis of past demographic trends projected into the future.

The COVID-19 pandemic and the resulting Australian Government closure of the international border from 20 March 2020, caused significant disruptions to the usual Australian population trends. This report uses some Australian Estimated Resident Population (ERP) estimates that reflect these disruptions. 

In the year July 2020 to June 2021, the overall population growth was much smaller than the years prior and in particular, there was a relatively large decline in the population of Victoria. ABS reporting indicates these were primarily due to net-negative international migration.

Please be aware that this change in the usual population trends may complicate your interpretation of statistics calculated from these ERPs. For example, rates and proportions may be greater than in previous years due to decreases in the denominator (population size) of some sub-populations.

More information is available from the ABS website.

The Multi-Agency Data Integration Project (MADIP) data asset contains linked national survey and administrative data from a range of Commonwealth Agencies, including healthcare, Census, social security payments, personal income tax, and mortality to create a comprehensive picture of Australia over time. The MADIP is managed under the custodianship of the Australian Bureau of Statistics. Information on specific datasets and linkage is available from the ABS website.

The MADIP datasets used in this report include:

• 2016 Census of Population and Housing
• National Death Index, 2011–2017.

Classification of dementia

The analysis presented in this report examines Census information on cultural and linguistic diversity among people with a dementia diagnosis recorded on their record in the National Death Index. Deaths registration data uses the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) to code cause of death information (see Table 2).

Exclusion criteria

The MADIP analysis was restricted to people identified in the linked data who:

• died with a dementia diagnosis after the 2016 Census period (September 2016 to December 2017)
• had a linked 2016 Census record
• were not recorded as an overseas visitor at the 2016 Census
• were aged 35 or over at the 2016 Census and
• were not missing country of birth information in the linked data.

Country of birth

Classification of country of birth in the analysis of MADIP in this report is obtained from the MADIP demography file and the 2016 census. Classification is based on the Standard Australian Classification of Countries 2016. More information on this classification is available from the ABS website.

In this analysis, people who died with dementia born in ‘English speaking’ countries include people born in Australia, New Zealand, United Kingdom, Ireland, United States of America, Canada and South Africa.

The National Aged Care Data Clearinghouse (NACDC) is an independent and central repository of national aged care data, mostly related to government-subsidised aged care programs operating under the Aged Care Act 1997.

The holdings include activity data for residential aged care programs, community-based aged care packages, aged care assessments and a number of other aged care programs and packages. The holdings also include recipient details, payment subsidies, and service (facility/provider) details. These data are refreshed annually (including a full replacement of historical data) by the Department of Health and Aged Care and are sourced from the Human Services payment systems, centralised client record systems and minimum datasets.

This report presents information from two key datasets as part of the NACDC – data from the National Screening and Assessment Form (NSAF) and from the Aged Care Funding Instrument (ACFI).

National Screening and Assessment Form data &ndash aged care assessments

The National Screening and Assessment Form (NSAF) is used to collect information on people who are interested in accessing government-subsidised aged care services co-ordinated through the My Aged Care system. This includes the initial screening of the interested person over-the-phone by My Aged Care contact centre staff, as well as information from either a home support assessment conducted by Regional Assessment Services or a comprehensive assessment conducted by Aged Care Assessment Teams for people who are found eligible to use of government-subsidised aged care services.

NSAF data are a new data source and further work is needed to develop the dataset into a comprehensive resource for statistical reporting. Due to data quality issues, only information relating to recent assessments were presented. Further development of the data may lead to revisions of the information presented in future reports.

The following should be considered when interpreting NSAF data presented in this report:

• Due to quality of earlier data, data on assessments completed between 2019–20 were presented in the aged care assessments chapter, and assessments completed between 2020–21 were presented in the BPSD chapter.
• While the information is reflective of people who completed a home support assessment or a comprehensive assessment, this does not equate to the number of people who were approved to use aged care services, or the number of people who were using aged care services that year.
• A small number of individuals were associated with the same assessment record. In these instances, assessment information was assumed to be identical for all individuals associated with the same assessment.
• A person was considered to have dementia if dementia was recorded as a health condition impacting their care needs (main condition or otherwise, see Table 3 for a full list of codes used). This may not capture everyone with dementia because not all people with dementia will have the condition impact their care needs.
• Individuals with missing date of birth or sex information were excluded.
• Due to small counts and confidentiality issues, intersex individuals were excluded from the analysis.
• Individuals with missing Indigenous status were not included in counts of Indigenous and non-Indigenous Australians.

1. People who had cognitive impairment recorded and no record of dementia were not counted as having dementia but were reported separately.

Aged Care Funding Instrument (ACFI) data – permanent residential aged care

The Aged Care Funding Instrument (ACFI) is used to allocate government funding to aged care providers based on the day-to-day needs of the people in their care. A snapshot of people in permanent residential aged care on 30 June 2020 showed that ACFI data captures almost all people living in permanent residential aged care (97%).

Although the ACFI is a funding instrument and not a diagnosis or comprehensive service tool, it does collect information on the assessed care needs of people in permanent residential aged care at the time of their appraisal. It is important to bear in mind that in some instances, not all services received will be captured in the ACFI assessment. An ACFI reappraisal can be conducted for various reasons, such as when a person has a significant change in care needs or after 12 months from when their classification has taken effect.

People in temporary respite care in an aged care facility do not have an ACFI assessment unless they also receive permanent care at some point. Therefore, information on residential respite care using the ACFI data is not presented. Further, the ACFI data do not capture people who are in certain specialised residential aged care programs, such as the Multi-Purpose Services Program and the National Aboriginal and Torres Strait Islander Flexible Aged Care Program.

Unless otherwise stated, all analyses using ACFI data excluded individuals with missing age and sex information. Individuals with missing information on their geographic location were only excluded from analysis by state/territory, remoteness, or socioeconomic areas.

Analyses on a person’s time in care are based only on the length of their latest episode of care. An episode of care is defined as a continuous service provided under the same program and care type for an individual. An episode of care ends when a person has a long admission to hospital, a change in care providers, returns to the community or dies.

Identifying dementia and other health conditions

The ACFI data captures up to 3 behavioural or mental conditions, and up to 3 medical conditions impacting care, which are also considered when determining the level of funding required. Health conditions are coded according to the Aged Care Assessment Program (ACAP) health condition list, and dementia is captured using the codes listed in Table 4.

As the ACFI only allows for up to 3 medical and 3 mental/behavioural conditions to be recorded, for some people it will not provide a comprehensive list of health conditions for that person.

The analyses presented in this report only use the latest ACFI assessment available for an individual’s latest episode of care, with the exception of dementia status. As dementia is an irreversible health condition, an individual was considered to have dementia if they had a record of dementia in any of their ACFI assessments. Dementia may not be captured in all ACFI assessments if at the time of a given assessment, 3 other mental/behavioural conditions had a bigger impact on a person’s care needs than their dementia.

Measuring care needs

As the ACFI is used to allocate funding, it captures the day to day care needs that contribute the most to the cost of providing individual care. Care needs are categorised as ‘nil’, ‘low’, ‘medium’, or ‘high’ based on responses to 12 questions across 3 domains: Activities of daily living, Cognition and behaviour, and Complex health care.

Ratings for each domain are used to determine the level of care funding and to assign care. People with high care ratings in a domain have more severe needs and require extensive assistance and care in that domain, whereas those with a low care rating have less severe needs.

Indigenous Australians and other culturally and linguistically diverse groups

Analysis of permanent residential aged care use among Indigenous Australians is based on whether people were identified as being Indigenous (i.e. Aboriginal and/or Torres Strait Islanders) or not (i.e. non-Indigenous), and excludes cases where the Indigenous status was unknown. ACFI data do not capture information on Indigenous-specific residential aged care services, such as the National Aboriginal and Torres Strait Islander Flexible Aged Care Program.

There are limitations to how well people with dementia from culturally and linguistically diverse backgrounds who are living in permanent residential aged care are identifiable in NACDC data. The permanent residential aged care content of this report only presents data and statistics based on whether people were from a non-English speaking background, which is determined based on whether they were born in a country classified as non-English speaking according to the Australian Bureau of Statistics Standard Australian Classification of Countries (SACC).

Rates and target populations

Where presented, rates refer to the number of people in permanent residential aged care as a proportion of the target population for residential aged care programs – that is, those aged 65 and over for all Australians, and those aged 50 and over for Indigenous Australians.

The National Hospital Morbidity Database (NHMD) is a compilation of episode-level records from admitted patient morbidity data collection systems in Australian public and private hospitals.

The data supplied are based on the National Minimum Data Set (NMDS) for Admitted patient care and include demographic, administrative and length of stay data, as well as data on the diagnoses of the patients, the procedures they underwent in hospital and external causes of injury and poisoning. The purpose of the NMDS for Admitted patient care is to collect information about care provided to admitted patients in Australian hospitals. The scope of the NMDS is episodes of care for admitted patients in all public and private acute and psychiatric hospitals, free-standing day hospital facilities, and alcohol and drug treatment centres in Australia. Hospitals operated by the Australian Defence Force, corrections authorities and in Australia’s off-shore territories are not in scope but some are included.

The counting unit in the NHMD is a separation, referred to as a hospitalisation in this report. Separation is the term used to refer to the episode of admitted patient care, which can be a total hospital stay (from admission to discharge, transfer or death) or a portion of a hospital stay beginning or ending in a change of type of care (for example, from acute care to rehabilitation).

Although hospital separations data are a valuable source of information about admitted patient care, they have limitations as indicators of ill health. Sick people who are not admitted to hospital are not counted and those who have more than 1 separation in a reference year are counted on each occasion. Therefore these data count episodes of care, not patients.

The hospital separations data do not include episodes of non-admitted patient care provided in outpatient clinics or emergency departments. However, patients in these settings may be admitted subsequently, with the care provided to them as admitted patients being included in the NHMD.

The years of data used for this report were for the financial years 2011–12 to 2020–21. Data were extracted in May 2022 and small changes may have occurred since this time.

A complete data quality statement for the NHMD is available online at meteor.aihw.gov.au.

Dementia-related hospitalisations

Data on diagnoses are recorded using the International Statistical Classification of Diseases and Related Health Problems, 11th Edition, Australian Modification (ICD-10-AM 11th edn).

Hospitalisations due to dementia were defined as hospitalisations where dementia was recorded as the principal diagnosis. Hospitalisations with dementia were defined as hospitalisations with at least 1 diagnosis of dementia, recorded as a principal and/or additional diagnosis.

Refer to Table 5 for relevant ICD-10-AM codes and coding rules for individual dementia types (the total number of hospitalisations for dementia is the sum of hospitalisations for the individual types of dementia). 

1. Indicates that the dementia type is valid regardless of whether the hospitalisation also includes this code.
2. Indicates that the dementia type is only valid when the hospitalisation also includes this code.
3. AIHW were advised by the AIHW Dementia Working Group to include hospitalisations with a principal diagnosis of G31 Other degenerative diseases of nervous system, not elsewhere classified and an additional diagnosis of dementia as a hospitalisation with a principal diagnosis of dementia. This was done previously for the AIHW Dementia in Australia 2012 report.

Hospitalisations for newborns without qualified days, hospital boarder and posthumous organ procurement (care types 7.3, 9.0 and 10.0), as well as where age was not reported or sex was recorded as intersex, indeterminate, not stated or inadequately described were excluded from the analysis.

Due to the onset of dementia occurring in older age groups, age-standardised rates were calculated from age 60 and over for the national population and age 40 and over for the Indigenous Australian population.

Palliative care hospitalisations were identified using the methodology followed in the AIHW 2021 web report Palliative Care Services in Australia, which is outlined in the Technical information section of that web report.

Geographical data, including state and remoteness area, refer to the usual place of residence of the patient. Data by Socioeconomic areas is based on the Socio-Economic Indexes for Areas (SEIFA) quintiles assigned by area, using the 2016 Index of Relative Socio-Economic Disadvantage (IRSD) scores.

Due to the small number of hospitalisations among Indigenous Australians by geographic area, rates of hospital separations with dementia as a principal diagnosis were examined over a 3-year period (2018–19, 2019–20 and 2020–21). Hospital separations with more than 3,000 bed days were excluded from the analysis of hospital separations among Indigenous Australians.

The National Integrated Health Services Information Analysis Asset (NIHSI AA) is a newly established enduring linked data asset managed under the custodianship of the AIHW, available for approved projects and analysts from the AIHW and participating jurisdictions.

The first version of this data asset (NIHSI version 0.5) contains linked data from 2010–11 to 2016–17 on:

• admitted patient care services (in all public and, where available, private hospitals), emergency department services and outpatient services in public hospitals for New South Wales, Victoria, South Australia and Tasmania, sourced from the Admitted Patient Care Database and the National Non-Admitted Patient Emergency Department Care Database
• Pharmaceutical Benefits Scheme (PBS) and Repatriation Pharmaceutical Benefits Scheme (R-PBS) national data
• Medicare Benefits Schedule (MBS) national data
• residential aged care national data from the National Aged Care Data Clearinghouse
• National Death Index data (contains data up to 31 December 2017).

Classification of dementia

The analysis presented in the GP and specialist services webpage compares the use of MBS services by people who had dementia with people who did not, based on identification (or lack thereof) of a dementia diagnosis evident in NIHSI version 0.5.

A person was identified as having dementia, where dementia was evident in NIHSI version 0.5 between 1 July 2010 and 30 June 2017 as:

• a principal or additional diagnosis in any hospital admission
• a principal or additional diagnosis in any emergency department presentation.
• They had 1 or more prescriptions for a dementia-specific medication.
• Dementia was recorded on their aged care funding assessment when they used a residential aged care service (either permanent residential aged care and/or respite residential aged care).

Table 6 outlines the codes used in each individual dataset to identify dementia and the classification system used in each dataset. Refer to the National Hospital Morbidity Database, Pharmaceutical Benefits Schedule and Aged Care Funding Instrument (for residential aged care) sections for more information on coding in these datasets.

Note: ICD-10-AM refers to the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification; ICD-9-AM refers to the International Statistical Classification of Diseases and Related Health Problems, Ninth Revision, Australian Modification; SNOMED CT-AU EDRS refers to the Systematized Nomenclature of Medicine – Clinical Terms – Australian version (Emergency Department Reference Set).

As dementia is thought to be under-recorded in administrative health data, the number of people with dementia is likely to be underestimated in this analysis. Additionally, as hospitals data were only available for New South Wales, Victoria, South Australia and Tasmania in NIHSI version 0.5, people with dementia from other states and territories who only had dementia recorded in a hospital service would not be included. Therefore, the group of people without dementia may include people with dementia, if dementia was not recorded in their administrative records in NIHSI version 0.5 in the time period analysed.

Exclusion criteria

Analysis of the NIHSI version 0.5 was restricted to people who were:

• aged 30 and over – due to dementia being uncommon in younger ages
• alive from 30 June 2016 to 31 December 2017 – due to differing service needs and usage among people in their last year of life
• recorded as using an MBS service in 2016–17
• not missing age and/or sex information entirely from the linked data.

If age and sex information was not recorded in the MBS service record, this information was collected from other data sources in NIHSI version 0.5 where possible.

It is acknowledged that there are a number of issues with comparing services used by people with dementia aged 30–64 to services used by people without dementia aged 30–64, as the ‘people with dementia’ group is skewed towards older ages. This should be considered when comparing service use between these two groups.

Classifying place of residence

To examine the impact that living in a permanent residential aged care facility has on health service usage, people with dementia and people without dementia were grouped based on whether or not they used a permanent residential aged care service in 2016–17.

The Living in residential aged care group includes people who were living in a permanent residential aged care facility for all, or part of the year in 2016–17 and used an MBS service that year. This does not include people who used respite services in a permanent residential aged care facility. All other people who used an MBS service in 2016–17 were considered to be in the Living in the community group. This group may include people who used respite services in a permanent residential aged care facility, as well as people who were living in other supported accommodation.

The group of people with dementia is more likely to include people who used residential aged care compared with those living in the community, as residential aged care data is a key source for identifying dementia in the analysis. This means that the group of people with dementia likely includes a larger proportion of those with a more severe form of dementia, and a smaller proportion of those who live in the community.

Medicare Benefits Schedule

The MBS data collection contains MBS claims data for Medicare services subsidised by the Australian Government. MBS services by age, sex, dementia status, type of service and leading specialist types among services provided by medical specialists were analysed for this report.

Table 7 outlines the variables used to identify GP and specialist services (by speciality type). For GP services, this includes GP and Vocationally Registered GP attendances, enhanced primary care and other non-referred attendances (including attendances in residential aged care facilities). Data on GP services from the MBS exclude services provided to Department of Veterans’ Affairs (DVA) card holders where care is reimbursed through the DVA, as well as services provided by salaried GPs in residential aged care or outpatients departments.

Specialty types were classified into subspecialties based on the Derived Major Specialty – used to allocate practitioners to a single specialty each period for statistical purposes. As specialists may have more than 1 registered specialty, service patterns for each specialist are used to classify the most appropriate specialty.

Data on dementia deaths were derived from the National Mortality Database (NMD) and analyses were based on the years 2010–2020. The NMD is maintained by the AIHW and holds records for deaths in Australia from 1964, and comprises information about causes of death and other characteristics of the person, such as sex, age at death, area of usual residence and Indigenous status. Cause of death data are sourced from the Registrars of Births, Deaths and Marriages in each state and territory, and the National Coronial Information System. They are compiled and coded by the Australian Bureau of Statistics (ABS) using the latest version of the International Statistical Classification of Diseases and Related Health Problems (ICD-10 for this report), an international standard agreed by the World Health Organization for defining and reporting causes of death. For more information about Australian mortality data, including scope and coverage of the collection and a quality declaration, please refer to Deaths, Australia (ABS cat. no. 3302.0) and Causes of death, Australia (ABS cat. no. 3303.0) available from the ABS website.Data on dementia deaths were derived from the National Mortality Database (NMD) and analyses were based on the years 2010–2020. The NMD is maintained by the AIHW and holds records for deaths in Australia from 1964, and comprises information about causes of death and other characteristics of the person, such as sex, age at death, area of usual residence and Indigenous status. Cause of death data are sourced from the Registrars of Births, Deaths and Marriages in each state and territory, and the National Coronial Information System. They are compiled and coded by the Australian Bureau of Statistics (ABS) using the latest version of the International Statistical Classification of Diseases and Related Health Problems (ICD-10 for this report), an international standard agreed by the World Health Organization for defining and reporting causes of death. For more information about Australian mortality data, including scope and coverage of the collection and a quality declaration, please refer to Deaths, Australia (ABS cat. no. 3302.0) and Causes of death, Australia (ABS cat. no. 3303.0) available from the ABS website.

Dementia deaths

Cause of death information is derived from conditions listed on Part I and Part II of a death certificate. Deaths due to dementia are deaths where dementia was recorded as the underlying cause of death (UCOD), that is, the disease or injury that initiated the train of events leading directly to death, or the circumstances of the accident or violence that produced the fatal injury.

The NMD also contains information on other associated causes of death (ACOD). These are all causes listed on the death certificate, other than the underlying cause of death, which were instrumental or significantly contributed to the death. Deaths with dementia refer to deaths where dementia was recorded as the UCOD or ACOD.

This report uses an expanded list of death codes attributed to dementia (that is, relative to the usual dementia codes used to report on deaths – G30, F01, and F03), with the aim of better capturing rarer dementia death types and mixed dementia (see Table 8). The AIHW created this expanded list in consultation with the AIHW Dementia Working Group and the ABS. Note that not all dementia types are reported separately in the report, due to confidentiality issues arising from small numbers.

Note: According to ICD-10 coding rules, the codes of F00 Dementia in Alzheimer’s disease and F05.1 delirium superimposed on dementia cannot be assigned as an underlying cause of death, but can be used to capture additional causes of death.

Analyses are based on the date on which the death occurred, and are compiled based on the state/territory of usual residence. The analyses exclude deaths for which the date of death, sex, or age, was not reported. Deaths are counted according to year of death occurrence. Deaths registered in 2017 and earlier are based on the final version of cause of death data; deaths registered in 2018 are based on the revised version; and deaths registered in 2019 and 2020 are based on the preliminary version. Revised and preliminary versions are subject to further revision by the ABS; deaths related to dementia in 2019 and 2020 are likely an undercount as a result of missing late registration.

Analyses of deaths among Indigenous Australians are based on whether people identified as being Indigenous (that is, Aboriginal and/or Torres Strait Islanders) or not (that is, non-Indigenous), and exclude deaths where the Indigenous status was unknown. In line with national reporting guidelines, data for Victoria, Tasmania, and the Australian Capital Territory have been excluded for all analyses involving Indigenous Australians, with the exception of analysis by remoteness areas, which includes all states and territories.

Due to the onset of dementia occurring mostly in older age groups, age-standardised rates were calculated from age 65 and over for the national population and age 50 and over for the Indigenous Australian population.

Leading underlying causes of deaths overall, and leading causes of death presented where dementia was an associated cause of death, are classified using an AIHW-modified version of Becker et al. (2006). This is based on recommendations of the World Health Organization (WHO) (Becker et al. 2006) with minor modifications to suit the Australian context.

Geography is based on area of usual residence – Statistical Local Area Level 2 (SA2). Unknown/missing includes deaths where place of usual residence was overseas, no fixed abode, offshore and migratory, and undefined.

Limitations

The number of people with dementia recorded on their death certificate, as presented in this report, is unlikely to include every person with dementia who died during the study period, even when dementia contributed to their death. One recent study using linked data showed that without linking to other datasets, mortality data only captured 31% of Australian women with dementia (Waller et al. 2017), while in another study, mortality data captured 67% of people with dementia who died in New South Wales and Victoria in 2013 (AIHW 2020). Further, coding changes and variations in certification practices over time have likely improved the accuracy of the attribution of deaths due to or with dementia in in recent years (ABS 2015).

Statistics based on Indigenous status should be interpreted with caution, as Indigenous identification is often incomplete, or is inconsistently reported across administrative data sets, including in the NMD (AIHW 2019). This report does not apply adjustments to account for Indigenous under-identification in the NMD, but does group deaths statistics for Indigenous Australians across 3 years of data to provide more robust estimates and avoid confidentiality issues related to small numbers.

References

ABS (Australian Bureau of Statistics) (2015) Causes of Death, Australia, 2013, ABS, Australian Government, accessed 17 August 2022.

AIHW (Australian Institute of Health and Welfare) (2019) Improving Indigenous identification in mortality estimates, AIHW, Australian Government, accessed 17 August 2022.

AIHW (2020) Patterns of health service use by people with dementia in their last year of life: New South Wales and Victoria, AIHW, Australian Government, accessed 17 August 2022.

Becker R, Silvi J, Ma Fat D, L'Hours A, & Laurenti R (2006) 'A method for deriving leading causes of death', Bulletin of the World Health Organization, 84, 297-304, doi:10.2471/blt.05.028670.

Waller M, Mishra G, and Dobson A (2017) 'Estimating the prevalence of dementia using multiple linked administrative health records and capture-recapture methodology', Emerging Themes in Epidemiology, 14(3), doi:10.1186/s12982-017-0057-3.

The Pharmaceutical Benefits Scheme (PBS) database contains government-subsidised medications dispensed under the PBS. The PBS database also includes medications supplied under the Repatriation Pharmaceutical Benefits Scheme (RPBS, available for eligible veterans, war widows/widowers and their dependants). The PBS database does not contain data on the dispensing of privately prescribed medicines, medicines to public hospital in-patients and over-the-counter medicines.

In this report, analyses were limited to people aged 30 and over who were dispensed at least 1 dementia-specific medication under the PBS between 30 June 2019 and 1 July 2020, as recorded in the PBS database. The statistics presented in the report refer to people who were dispensed medications, which may not equate to the number of prescriptions for medications prescribed by medical professionals (as not all prescriptions are dispensed).

The following should be considered when interpreting prescriptions data presented in this report:

• A very small proportion of records with missing patient identification, age and sex information were excluded from the analysis.
• As a person’s age (and subsequent age group) may change in a single year, a person’s age in their earliest record in the year was used as their age for the entire year.
• As a person may move between states and territories in a single year, the state or territory recorded in a person’s earliest record in the year was used as their geographical location for the entire year.
• As people may be prescribed dementia-specific medication by different medical specialists in a single year, people may be counted multiple times in some analyses.
• People who were dispensed dementia-specific medication for the first time includes people who had not been dispensed a dementia-specific medication since 2005–06.

Anatomical Therapeutic Chemical (ATC) Classification

PBS items were mapped to the Anatomical Therapeutic Chemical (ATC) Classification, a classification system for medicines maintained by the World Health Organization. The ATC classification groups medicines according to the body organ or system on which they act, and their therapeutic and chemical characteristics. Medicines are given an ATC classification in the Schedule of Pharmaceutical Benefits according to their main therapeutic use in Australia as registered with Therapeutic Goods Administration and listed on the PBS. More information on the ATC classification system can be found at: The World Health Organization website.

Dementia-specific medications included in this report and their corresponding ATC codes include:

• N06DA02 – Donepezil
• N06DA03 – Rivastigmine
• N06DA04 – Galantamine
• N06DX01 – Memantine.

Table 9 shows all the medications presented in this report by ATC1 level (for example, Alimentary tract and metabolism) and by ATC2 level (for example, Drugs for acid related disorders).

Table 9: Medications defined in this report, by ATC code.

The Survey of Disability, Ageing and Carers (SDAC) is a national survey run by the Australian Bureau of Statistics (ABS) that has been collecting information since 1981.

The survey collects detailed information from three key populations:

• people with disability – people who have at least one limitation, restriction or impairment, which has lasted, or is likely to last, for at least 6 months and restricts everyday activities
• people aged 65 years and over
• carers – people who provide unpaid informal assistance on a regular basis to people with a disability or people aged 65 years and over.

The information presented in this report was sourced from the ninth survey, conducted in 2018. Previous surveys were conducted in the years 1981, 1988, 1993, 1998, 2003, 2009, 2012 and 2015.

Survey collection

The 2018, SDAC was conducted in two components based on a person’s place of residence:

• Household component – people living in private dwellings (such as houses, flats, home units, townhouses), as well as self-care components of retirement villages
• Cared accommodation component – people living in residential aged care facilities, hospitals and other ‘homes’ who had been, or were expected to be, living there, or in another health establishment, for at least three months.

There were 65,805 people included in the 2018 SDAC – 54,142 people from the household component and 11,663 people living in cared accommodation.

The household component of the survey was interviewer-administered, and involved collecting information from all people residing in the household who were part of the key populations listed above, as well as residents who provided informal care and assistance with the self-care, mobility and communication (core-activities) for a co-resident, and were considered to provide a greater level of care than others for that care recipient (considered the primary carer). Proxy interviews were done for; children under 15 years of age; children aged 15–17 whose parent or guardian did not agree to them being personally interviewed and people who were unable to answer for themselves due to their disability (illness, impairment, injury or language problems). In this report, people with dementia who were included in the household component are referred to as ‘living in the community’.

The cared accommodation component was administered via paper forms mailed directly to selected establishments. As such, the information collected was based on staff members’ knowledge of the residents and from clinical and administrative records.

Further information on the 2018 SDAC method of collection can be found at: Disability, Ageing and Carers, Australia: Summary of Findings methodology, 2018.

Reporting of dementia

In this report, a person was considered to have dementia in the SDAC 2018 if, the following conditions were reported as a health condition (main condition or otherwise):

• Dementia – SDAC diagnosis code 0511
• Alzheimer’s disease – SDAC diagnosis code 0605
• Dementia with Lewy bodies – SDAC diagnosis code 0615
• Frontotemporal dementia – SDAC diagnosis code 0616

It is possible that some people with certain types of dementia (such as dementia in Huntington’s disease) may have only had the causal condition coded and would not be identified as having dementia. Reporting of dementia by type from the SDAC was considered unsuitable, due to the self-reporting nature of the household component of the survey and the low numbers observed for some of the dementia types.

As the SDAC does not perform clinical assessment of survey respondents, it is acknowledged the SDAC will under-estimate people in the early stages of dementia, particularly those in the community, who have not received a formal diagnosis. In addition, some survey respondents may choose not to disclose their dementia.

Health condition coding in the SDAC is based on the International Classification of Diseases and Health Conditions, 10th Revision (ICD-10). A full list of long term health conditions and equivalent ICD-10 codes used in the SDAC is found at: Disability, Ageing and Carers, Australia: Summary of Findings methodology, 2018.

Limitations and level of disability

The SDAC captures information on peoples’ limitations and levels of disability. Limitations were assessed in terms of what a persons’ level of difficulty was in undertaking each of a number of tasks, their need for assistance in each task and whether aids or equipment were used (Table 10). These tasks were grouped into either core-activities (self-care, mobility or communication related tasks) or other activities.

Source: Australian Bureau of Statistics, Disability, Ageing and Carers, Australia: Summary of Findings methodology 2018

Level of disability

The level of disability (or limitation) is based on the degree of assistance or supervision required by the survey respondent in one or all core activities. The level of disability is grouped into 4 categories:

• Mild limitations: the person needs no help and has no difficulty with any of the core activity tasks, but uses aids or equipment for core tasks, or has other limitations (such as difficulty walking short distances, unable to easily bend over or needs help with using public transport).
• Moderate limitations: the person needs no help, but has difficulty with a core activity task.
• Severe limitations:  the person sometimes needs help with a core activity task, and/or has difficulty understanding or being understood by family or friends, or can communicate more easily using non-spoken forms of communication.
• Profound limitations: the person is unable to do, or always needs help with, a core activity task.

A person's overall level of core activity limitation is determined by their highest level of limitation in these activities.

Reporting on primary carers

This report focuses on information from the SDAC on primary carers of people with dementia.

The SDAC defines a primary carer as the person aged 15 or over who provides the most informal, ongoing assistance with one or more core activities (mobility, self-care and communication) for a person with disability. The assistance had to be ongoing, or likely to be ongoing, for at least 6 months. SDAC only collects information on primary carers who live in the same household as their care recipient.

Primary carers excludes people who provide formal assistance (on a regular paid basis, usually associated with an organisation).

The SDAC does not capture information about people who provide informal care to those with dementia living in residential aged care facilities.