DEMENTIA AND DEATH IN AUSTRALIA

Dementia is a chronic illness that affects the brain, leading to health complications and often death. It is one of the most common diseases in the elderly and a major cause of disability (Endnote 7). As Australia’s population ages, the incidence of dementia has increased and this is expected to continue.

These trends are reflected in Australia’s changing mortality profile. Dementia became Australia’s second leading cause of death in 2013, up from fourth in 2006. Further increases are expected in future, with dementia predicted to become Australia’s leading cause of death over the next few years. This fact sheet provides further information about dementia-related deaths in Australia.

Some quick statistics

There were 159,052 deaths in Australia in 2015. Almost 1 in 12 had dementia as the underlying cause of death¹ (12,625 deaths). This equates to around 35 deaths per day. Individuals who died from dementia were more likely to be over 85, and were also more likely to be female. For a further 12,437 deaths, dementia was a factor in the death but not the underlying cause. Based on research presented by the World Health Organisation, ‘dementia’ described in mortality data includes vascular dementia, Alzheimer’s disease leading to dementia, and dementia stated on a death certificate without mention of cause (Endnote 4).

The dementia death rate is increasing

Measured as a standardised death rate, dementia accounted for 40.1 deaths per 100,000 people in 2015 compared to 28.6 in 2006. When compared to other leading causes of death over this period, the mortality rate for dementia has increased by the largest margin. In fact, rates for the top three leading causes in 2006 (heart disease, lung cancer and strokes) had decreased by 2015. As a result dementia has moved from the fourth to the second leading cause of death in Australia.
Measured as a standardised death rate, dementia increased from 28.6 deaths per 100,000 in 2006 to 40.1 in 2015. Over this period, the death rate for the remaining top five leading causes of death either decreased or remained relatively stable. This has resulted in dementia moving from the fourth to the second leading cause of death in Australia from 2006 to 2015.



Dementia mostly affects the elderly

The median age of those who died from dementia in 2015 was 88.6 years, compared to 81.9 years for all deaths. Around 70 percent of all dementia deaths occurred in those 85 years of age and over and roughly another quarter occurred among people aged 75 to 84 (see graph, below). This indicates that around 95 percent of all dementia deaths occur after age 74.



More women die from dementia than men

In 2015 the standardised death rate from dementia for men was 35.4 deaths per 100,000 and 42.9 for women. Women therefore die from dementia at a rate 1.2 times greater than that of men. Given the increased risk of dementia at older ages, it is expected that the longer life expectancy of women (84.5 years compared to 80.4 years for men (Endnote 1)) would be a contributing factor to this sex bias.

Complications associated with dementia

Deaths from dementia mostly occur because of complicating factors. These factors are often associated with issues such as immobility, incontinence, instability, malnutrition and impaired immune function. Sufferers can become frail, have breathing difficulties, and develop infections, all of which can lead to death. In 2015, pneumonia² was the most common complication contributing to dementia deaths in Australia (2,707 cases, or 21.4 percent).

Dying with dementia compared to dying from dementia

Mortality data is generally presented by underlying cause, the single condition among those listed on the death certificate that started the chain of events leading to death. Depending on the certifying doctor’s opinion and agreed international mortality coding rules, dementia can be assigned as an underlying cause of death (‘dying from dementia’), or as a co-morbid condition contributing to death (‘dying with dementia’). Specifying the number of deaths in each group helps estimate the overall prevalence of dementia in Australia's mortality profile.

In 2015, a total of 12,625 people died from dementia, while 12,437 died with dementia (usually from other underlying causes like ischaemic heart disease or stroke). This equates to 25,062 deaths (15.8 percent of all deaths) where dementia was involved either as an underlying cause or contributory factor. Dementia therefore played a role in roughly every sixth death in Australia.

More people are living with dementia

According to AIHW (2012), in 2015 there were an estimated 342,800 people living with dementia in Australia, an increase of nearly 100,000 people since 2005, and more than the number of people currently living in the Northern Territory (Endnote 2). This report also notes that among Australians aged 65 and over, almost one in ten may have dementia, while among those aged 85 and over, the number is closer to three in ten. The survival time from the onset of dementia to death varies widely and can range from three to 13 years (Endnotes 5 and 8).

The prolonged illness and disability impacts of dementia on the general population are also substantial. In 2011, dementia was the third leading cause of disability burden in Australia and those with dementia depended on approximately 200,000 informal carers (Endnote 2). According to Alzheimer’s Australia, dementia cost an estimated $8.8 billion in direct expenditure in 2016, and is forecast to rise to $16.7 billion by 2036 (Endnote 3).

Some good news

Older Australians can generally expect to live longer and healthier lives than previous generations. According to the Australian Health Survey (ABS, 2013) most Australians aged 65 and over consider themselves to be in relatively good health (Endnote 1). While the risk of dementia increases with age, this also reflects the reduction in mortality rates from other diseases and conditions such as heart disease and strokes.

With the prevalence of dementia increasing, it has been recognised both in Australia and globally as a health priority area (Endnotes 6 and 9). As a result, considerable resources are now being committed to the investigation of potential prevention pathways and treatments options for dementia.


Footnotes

1. The ABS currently uses the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) to classify and code causes of death. ‘Dementia’ deaths are tabulated from three sub-categories each with a specific ICD-10 code; Vascular dementia (F01), Alzheimer’s disease (G30), and unspecified forms of dementia (F03).

2. Pneumonia here is defined as ICD-10 codes J12 to J18: Viral pneumonia, not elsewhere classified (J12); Pneumonia due to Streptococcus pneumoniae (J13); Pneumonia due to Haemophilus influenza (J14); Bacterial pneumonia, not elsewhere classified (J15); Pneumonia due to other infectious organisms, not elsewhere classified (J16); Pneumonia in diseases classified elsewhere (J17); Pneumonia, organism unspecified (J18).

Bibliography

1. ABS (Australian Bureau of Statistics) 2016, Life Tables, States, Territories and Australia, 2013-2015, cat. no. 3302.0.55.001, ABS, Canberra.

2. AIHW 2012, Dementia in Australia. Cat. no. AGE 70. Canberra: AIHW.

3. Alzheimer's Australia 2017. Economic cost of dementia in Australia 2016-2056. Viewed 26th May 2017 <https://www.fightdementia.org.au/files/NATIONAL/documents/The-economic-cost-of-dementia-in-Australia-2016-to-2056.pdf>

4. Becker R, Silvi J, Ma Fat D, L'Hours A and Laurenti R. A method for deriving leading causes of death. Bulletin of the World Health Organisation. April 2006, 84 (4).

5. Brodaty H, Seeher K & Gibson L (2012). Dementia time to death: a systematic literature review on survival time and years of life lost in people with dementia. International Psychogeriatrics, 24(7):1034-45.

6. Department of Health 2017. Dementia. Viewed 26th May 2017 <https://agedcare.health.gov.au/older-people-their-families-and-carers/dementia>

7. Fratiglioni L, De Ronchi D, Aquero-Torres H 1999. Worldwide Prevalence and Incidence of Dementia. Drugs & Aging. 1999 Nov; 15 (5): 365-375.

8. Staekenborg S, Pijnenburga YAL, Lemstra AW, Scheltens P and vd Flier, Wiesje M (2016). Dementia and Rapid Mortality: Who is at Risk? Journal of Alzheimer’s Disease vol 53(1):135-142.

9. World Health Organisation and Alzheimer's Disease International 2012 . Dementia: A public health priority. Viewed 25th May 2017 <http://apps.who.int/iris/bitstream/10665/75263/1/9789241564458_eng.pdf?ua=1>