How many people who died due to COVID-19 also had dementia?
- Of the 858 people who died due to COVID-19 in the first 10 months of 2020, 30% also had dementia (140 women and 117 men).
- Among people who died due to COVID-19, those with dementia tended to be older.
- Among people who died due to COVID-19, those with dementia were less likely to have had acute respiratory conditions (caused by COVID-19) recorded on their death certificate.
- Most people aged 75 years and over who died due to COVID-19 with dementia lived in Greater Melbourne, and many likely lived in one of the 61 residential aged care homes that experienced fatal COVID-19 outbreaks.
Background and key definitions
COVID-19 is a disease caused by a new type of coronavirus—a large group of viruses known to cause respiratory infections. About 99% of COVID-19 deaths in Australia have been confirmed by laboratory testing (ABSa 2020). The data used in this report include both medical doctor and coroner certified deaths due to COVID-19.
Due to the public health importance of COVID-19, the WHO has directed that the new coronavirus strain be recorded as the underlying cause of death, that is, the main disease or condition causing death, when it is recorded as having caused or contributed to death. In Australia, it is rare for COVID-19 to be coded as an associated cause of death (ABS 2020b).
Data and period of analysis
This report uses ABS provisional mortality data, covering deaths that occurred in the first 10 months of 2020 (between 1 January and 27 October). This includes most deaths that occurred from the beginning of the pandemic in Australia to the end of the second Victorian outbreak in 2020.
This report refers to 2 ‘waves’ of the COVID-19 pandemic in Australia—by this we mean a rapid increase in the number of infections, a peak, and then a decline in the number of infections:
- wave 1 (from 4 March to 26 May) occurred mostly in New South Wales, was shorter than wave 2, and resulted in fewer COVID-19 deaths than wave 2
- wave 2 (from 24 June to 27 October) occurred mostly in Victoria, led to extended lockdown measures particularly in Greater Melbourne, and was when most of Australia’s COVID-19 deaths occurred.
People who died due to or with dementia
People with dementia may die due to their dementia or from other conditions or injuries (such as influenza or a fall), so dementia may be recorded as an underlying or an associated cause of death on death certificate. In this report, people with dementia are looked at in two groups based on where dementia was recorded in the death certificate:
- deaths due to dementia refer to deaths where dementia was the underlying cause of death
- deaths with dementia refer to deaths where there was any record of dementia (as the underlying cause or an associated cause of death). About 3 in 5 of these deaths were deaths due to dementia.
Most of the information in this report relates only to deaths that were certified by a medical doctor. At the time of writing, coroner-certified deaths were only available when a person died due to COVID-19 (and these are included in this report). However, roughly 1–2% of deaths where dementia is recorded as an underlying cause of death are usually certified by a coroner. While the analyses in this report are unlikely to be significantly affected by missing coroner certified deaths, the data are considered preliminary and subject to change, and results should be interpreted with caution. In an unknown proportion of cases, dementia may not be recorded at all, either because it is incorrectly missed from the death certificate or because the dementia legitimately did not contribute to death. As a result, the number of people with dementia recorded on their death certificate will not capture every person with dementia who died during the pandemic.
State and territory governments and the federal Department of Health publish daily updates on the number of COVID-19 cases and deaths in Australia, and fortnightly reports on outbreaks in residential aged care homes, and these resources have provided the public with timely data on the impact of the pandemic on older people in Australia (Department of Health 2020; Department of Health 2021). There is, however, less information on how COVID-19 has specifically affected people with dementia (Parliament of Australia 2020). People with dementia are more likely to contract COVID-19 as well as to develop severe COVID-19 than people without dementia due to various reasons, including that:
- there has been a high prevalence and spread of the virus in some aged care homes
- people with dementia tend to have other comorbidities, and these may increase their risk of developing severe COVID-19 symptoms (AIHW 2020a)
- people with dementia may find it more difficult to understand and follow public health recommendations related to reducing the chances of contracting COVID-19
- a gene common in people with dementia (the APOE e4 genotype), is also linked to an increased probability of developing severe COVID-19 (Kuo et al. 2020a; Kuo et al. 2020b; Numbers and Brodaty 2021; Yang et al. 2021).
In Australia, people with dementia are estimated to account for over half of people living in permanent residential aged care (AIHW 2020a). While less than 1 in 10 cases of COVID-19 across Australia have been of people living in residential aged care, they accounted for over 7 in 10 COVID-19 deaths during 2020 (Department of Health 2021). Outbreaks in aged care homes have placed residential aged care homes under strict public scrutiny and pressure, particularly in light of the Royal Commission into Aged Care Quality and Safety’s interim report ‘Neglect’, which found that Australia’s aged care system has failed to consistently provide safe and quality care to Australians, and has called for a fundamental overhaul of Australia’s aged care system (Royal Commission 2020). While most people with dementia are thought to live in the community and not in residential aged care homes, those with more advanced dementia and more frail health tend to live in residential aged care homes due to their higher care needs.
This section presents deaths due to COVID-19 in Australia (that is, where COVID-19 was the underlying cause of death recorded on a person’s death certificate) and compares these deaths by whether or not dementia was also recorded as an associated cause of death.