6: Dementia severity and progression
There are 3 main activities proposed to improve available data on dementia severity and progression. These include activities to:
- 6a: Determine outcomes and transitions of care for people experiencing BPSD using linked data
- 6b: Validate data on select behaviours collected in aged care assessment data
- 6c: Assess feasibility to incorporate measures of behaviours associated with dementia in existing national surveys or population-based studies
Another activity in this plan which may also improve data on dementia severity and progression is:
- 3a: Incorporate dementia data in enduring linked data assets to meet the needs of dementia monitoring (detailed in Dementia prevalence and incidence)
Each activity provides information on the intended outcome, level of investment required, timeframe for completion of the activity and who is responsible for undertaking the activity.
Activity 6a: Determine outcomes and transitions of care for people experiencing BPSD using linked data
Using the enduring linked data assets (detailed in Dementia prevalence and incidence), key health and welfare statistics for people experiencing BPSD can be identified and reported on by different Neuropsychiatric Inventory (NPI) domains. Hospitalisations, mortality outcomes, service use and interactions with, and transitions of care through, the various care systems can be examined to provide greater understanding of BPSD. The extent to which people experiencing BPSD can be identified is dependent on the data sources included in the enduring linked data asset. The inclusion of data from Dementia Support Australia is a worthy first stage as this allows identification of people who have accessed key national behaviour support programs. Identifying people who have experienced BPSD but who have not accessed these services is more difficult and reliant on identification in other data sources. This is reliant on further data development described in subsequent activities.
| Outcome | Better data on outcomes and transitions of care for people with dementia experiencing BPSD. |
|---|---|
| Level of investment | Low: This activity involves analysis only, therefore this requires low investment. |
| Timeframe | Short-medium |
| Responsible stakeholder | AIHW NCMD; Dementia Support Australia; academic researchers |
| Progress | The AIHW have worked with Dementia Support Australia to create a pilot linkage between DSA data and the National Health Data Hub (see Activity 3a). The AIHW is using this pilot linkage in an analytical project to understand use of health and aged care services and transitions of care for people experiencing BPSD. Results from this work are expected by early 2027. Outcomes will inform next steps for this activity, including the potential for developing an enduring data set. |
Activity 6b: Validate data on select behaviours collected in aged care assessment data
Using the enduring linked data assets (detailed in Dementia prevalence and incidence), this activity involves validating data on behaviours collected in aged care assessment data with the gold standard Neuropsychiatric Inventory (NPI) data collected by Dementia Support Australia. Currently, aged care assessments include questions on a range of psychological symptoms, measured by self-reported frequency, that broadly align with the NPI. Linkage can be used to compare data on these psychological variables for Dementia Support Australia clients who have also been formally assessed with the NPI. While BPSD can fluctuate over time and this may pose limitations to direct comparisons, validation will provide insight into how the self-reported frequency of psychological symptoms recorded aligns with the NPI’s severity, frequency, and carer distress information, and more broadly will evaluate aged care assessments as a data source for capturing BPSD. This may also inform what enhancements could be made to aged care assessments to monitor dementia severity.
| Outcome | Better understanding of behaviours data collected in aged care assessment data and their use for national monitoring of BPSD in Australia. |
|---|---|
| Level of investment | Low: This activity involves analysis only therefore this requires low investment. |
| Timeframe | Short-medium |
| Responsible stakeholder | AIHW NCMD; Dementia Support Australia |
| Progress | The AIHW have worked with Dementia Support Australia to create a pilot linkage between DSA data and the National Health Data Hub (see Activity 3a). Activity 6a is the current priority for this pilot linkage, however, pending outcomes from activity 6a, an enduring linkage may be developed and this activity could be pursued in future analyses. |
Activity 6c: Assess feasibility to incorporate measures of dementia severity and progression in existing national surveys or population-based studies
This activity involves working to incorporate measures of dementia severity, progression and behaviours associated with dementia in existing national surveys or population-based studies. The ABS Survey of Disability, Ageing and Carers has been identified as a possible national source due to its population scope, coverage, capture of people with dementia in community and residential aged care and collection of data from carers. However, other population-based studies may be found suitable stemming from Activity 3c described in Dementia prevalence and incidence. This activity requires extensive consultation on the feasibility of implementing measures to capture this information in existing data collections.
Following feasibility assessment and consultation, the next stage would be to implement the new measures in the data collection and assess findings.
| Outcome | National data on dementia severity, progression and behaviours, including for people living with dementia who do not currently access behavioural support services. |
|---|---|
| Level of investment | Low: This initial feasibility assessment requires low investment. |
| Timeframe | Short (<2 years) |
| Responsible stakeholder | AIHW NCMD, ABS and other data collectors |
| Progress | Not started. Future work could explore options to utilise artificial intelligence to extract information about dementia type, severity, progression and comorbidities from clinical notes. |
Symptoms of dementia will vary between people and can vary day to day for the same person. However, each person will experience progressive cognitive and physical decline. The rate of decline will vary due to numerous factors such as personal characteristics, dementia type, age at diagnosis, existing health conditions, care and living arrangements and access to health services.
Data on severity and rate of progression will indicate the level of support required, when increases in support are projected to be needed, and may support research into risks for more rapid progression, or eligibility for clinical trials or treatment.
There is no consistent classification of dementia severity and various models are used. In the 3-stage dementia severity model:
- mild dementia is defined by cognitive impairment and poor performance on objective cognitive assessments that represent a decline from the past; however, independence in basic activities of daily living is maintained
- moderate dementia has more distinct symptoms and impacts on activities of daily living
- advanced dementia includes health and functional declines requiring assistance in activities of daily living.
Other classification systems use 7 stages that include stages occurring before a dementia diagnosis (Reisberg et al. 1982).
Data on dementia severity and progression will inform service needs and planning and may assist in assessing the effectiveness of interventions designed to reduce or slow dementia progression, and factors leading to increased severity or progression. Current data focus on functional abilities and level of assistance required to perform tasks across different domains (such as self-care, mobility and communication). These data are currently captured in aged care assessment data and the Australian Bureau of Statistics’ (ABS) Survey of Disability, Ageing and Carers. Aged care assessment data also contain some information on current levels of support, daily life, health, behaviours, memory and goals (My Aged Care).
In addition, there is a lack of information about people in the early stages of dementia or cognitive impairment, including the diagnosis and early disease management process due to poor recognition of symptoms and early assessment (as outlined in Timeliness of dementia diagnosis). Current data sources tend to capture people with more severe dementia, when they engage with hospital and aged care services.
Behavioural and psychological symptoms of dementia
Behavioural and psychological symptoms of dementia (BPSD) refer to non-cognitive symptoms (such as aggression, agitation, apathy, depression and disinhibited behaviours), that are common across all types of dementia and have no singular cause. The type and severity of symptoms can vary over the course of the illness, and on a day-by-day basis. The symptoms can have a major impact on the person with dementia and their carers (AIHW 2025).
Most people living with dementia will experience at least some level of BPSD as their dementia progresses. BPSD has a range of non-cognitive symptoms and is often associated with complex care needs. The Neuropsychiatric Inventory (NPI) is the primary measure of BPSD within clinical settings in Australia. It assesses a wide range of behaviours, rating severity, frequency, and carer distress for 12 domains. Currently, Dementia Support Australia are the only national data source that collect NPI information for people who experience BPSD, although, these are only of people accessing their services. Some data on select behaviours are captured in aged care assessment data. Improved data on BPSD will inform planning for the health and aged care systems including national behaviour support programs currently managed by Dementia Support Australia such as the Dementia Behaviour Management Advisory Service, Severe Behaviour Response Teams, and the Specialist Dementia Care Program (AIHW 2025).
AIHW (2025) Dementia in Australia, AIHW, Australian Government, accessed 15 October 2025.
Reisberg B, Ferris S, de Leon M and Crook T (1982) ‘The global deterioration scale for assessment of primary degenerative dementia’, American Journal of Psychiatry, 139(9):1136–1139, doi:10.1176/ajp.139.9.1136.