How multiple conditions contribute to death
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Australians who die of chronic conditions often have multiple causes contributing to their death.
Interactions between co-occurring conditions can impact mortality outcomes for people living with multimorbidity.
Australians who die of chronic disease often have more than one cause of death recorded on their death certificate. Examining all the causes of death listed on a person’s death certificate can aid an understanding of how multiple conditions contribute to death.
In 2023, on average 3.3 causes were recorded on each death certificate. The average number of causes per death generally increased with age from 1.8 for those aged 0–14 years to 3.5 in those aged 85 years and over (AIHW 2025).
Figure 16 highlights some of the most common associated causes of death for selected chronic diseases as the underlying cause.
For more information, see Deaths in Australia – How many deaths and how many causes?
The underlying cause of death 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. Deaths are referred to here as 'due to' the underlying cause of death.
Associated causes of death are all causes listed on the death certificate, other than the underlying cause of death. They include the direct cause (the immediate cause and any intervening causes), and contributory causes (conditions which contributed to the death but were not related to the disease or condition causing the death).
The AIHW National Mortality Database was used to analyse chronic condition deaths. For more information on the data source, see Technical notes.
Leading causes of death are based on underlying causes of death and classified using an AIHW-modified version of Becker R, Sivli J, Ma Fat, L'Hours A, Laurenti R. 2006. A method for deriving leading causes of death. Bulletin of the World Health Organization 84: 297–304. For more information see Deaths in Australia – Leading causes of death: classifying causes of death.
Figure 16: Commonly reported associated causes of death for selected chronic conditions as the underlying cause, 2021–2023
This figure shows that among deaths due to asthma common additional causes included influenza and pneumonia (22%), chronic obstructive pulmonary disease (COPD) (22%) and heart failure (21%). Among deaths due to COPD common additional causes included heart failure (24%), influenza and pneumonia (19%) and coronary heart disease (18%).
Notes:
- Heart failure is short for 'Heart failure and complications and ill-defined heart disease'.
- For data and footnotes, see Table MM12 in the Data tables.
Figure 16 shows that in 2021–2023 among deaths due to cerebrovascular disease:
- 27% had hypertensive disease listed as an associated cause – hypertension is a known risk factor for cardiovascular disease (AIHW 2024b).
- 16% had dementia (including Alzheimer’s disease) listed as an associated cause – cerebrovascular diseases which affect blood flow to the brain are known risk factors for vascular dementia (AIHW 2016, AIHW 2024a).
Among deaths due to diabetes in 2021–2023:
- 40% had coronary heart disease and 33% had hypertensive disease listed as an associated cause – a complex interplay between the effects of chronic kidney disease and cardiovascular disease means that each condition is a risk factor for the other (Kidney Health Australia 2022).
- 39% had kidney failure listed as an associated cause – diabetes is a common cause of chronic kidney disease with about half of all people with diabetes developing chronic kidney disease (Kidney Health Australia 2022).
Among deaths due to liver cancer in 2021–2023:
- 27% had liver disease listed as an associated cause.
- 11% had diabetes listed as an associated cause – non-alcoholic fatty liver disease included in the liver disease group is risk factor for developing diabetes (Mantovani 2021).
AIHW (Australian Institute of Health and Welfare) (2016) Contribution of vascular diseases and risk factors to the burden of dementia in Australia: Australian Burden of Disease Study 2011, AIHW, Australian Government, accessed 3 March 2025.
AIHW (2024a) Dementia in Australia, AIHW, Australian Government, accessed 3 March 2025.
AIHW (2024b) Heart, stroke and vascular disease: Australian facts, AIHW, Australian Government, accessed 3 March 2025.
AIHW (2025) Deaths in Australia, AIHW, Australian Government, accessed 8 May 2025.
Kidney Health Australia (2022) Fact sheet: Make the link: chronic kidney disease, diabetes and cardiovascular disease. Viewed 3 March 2025.
Mantovani A, Petracca G, Beatrice G, Tilg H, Byrne CD and Targher G (2021) ‘Non-alcoholic fatty liver disease and risk of incident diabetes mellitus: an updated meta-analysis of 501,022 adult individuals’. Gut. 2021 May;70(5):962-969, doi: 10.1136/gutjnl-2020-322572.