Summary
Understanding how and why Australians die provides insights into the health of the population. This can lead to a better awareness of what health conditions have the biggest impact on the community, and can aid health services and decision makers to develop strategies and interventions to reduce the impact of diseases and promote better health.
The question ‘What do Australians die from?’ is more complicated than it sounds and can vary depending on what we want to know. We may want to know what specific conditions ultimately end a person’s life, which disease or injury is responsible for initiating a person’s death, what risk factors lead to the disease or injury that caused a person’s death, or if any conditions contributed to their death in other ways. This report answers these questions and highlights the most common causes involved in the deaths of Australians.
Traditionally, statistics about how people die are based on the initiating or ‘underlying’ cause of death (see Cause of death terminology). But medical death certificates contain other information that can be useful in understanding why a death occurred. For example, while the underlying cause of death for a person might be coronary heart disease, the death certificate might also record the health condition that led directly to death (such as acute myocardial infarction) referred to as ‘direct’ causes of death in this report. Other conditions that significantly contributed to the death such as diabetes, alcohol use disorders and other contextual factors (referred to as ‘contributory’ causes in this report) may also be recorded on the death certificate. Consideration of all these cause types (underlying, direct, and contributory) is referred to as ‘multiple’ causes of death (see Cause of death terminology below).
Cause of death terminology
Underlying cause: the condition which initiated the chain of events leading to death. It provides a significant point in the sequence of events where an intervention, if available, could take place to prevent the death from occurring.
Direct causes: the health events that arise from the underlying cause. They can relate to consequences and complications of the underlying cause. Some direct causes reflect the health events experienced at the end of life, or conditions experienced for lengthy periods before death.
Contributory causes: the conditions that significantly contributed to the death but were not in the chain of events leading to death. Typically, these causes relate to prior or co-existing long-term health conditions, and social and other circumstances that were involved in the death. They highlight additional health conditions that could be the focus of prevention strategies, for example, the causes that contribute to chronic disease deaths.
Multiple causes: all the causes involved in causing the death (underlying, direct, and contributory). When assessed in combination these describe the most common conditions involved in causing deaths.
Throughout this report, each of the cause types described above is presented in terms of the percentage of deaths it caused as multiple, underlying, direct, or contributory causes. It is important to note that each death can have more than one multiple, direct, or contributory cause.
This report uses all of the information included on the medical death certificate to provide new insights into the question ‘What do Australians die from?’ It shows that the answer to this question is very different depending on whether the focus is the diseases or causes that are responsible for initiating the pathway to death (underlying cause), the conditions that lead directly to death (direct causes), the causes that contribute to death (contributory causes) or all of the causes involved in a death (multiple causes). The report also looks at what risk factors and psychosocial factors contribute to deaths in Australia. Using different ways of looking at causes of death can enhance our understanding of the roles played by different diseases and conditions in a person’s health and in their death.
The involvement of multiple causes in a person’s death and how this information is recorded on a person’s death certificate is best illustrated using an example.
Example of multiple conditions involved in causing death
Consider a person who has lung cancer as the underlying cause of death. However, they also had hypertension (high blood pressure) and diabetes and had been a smoker. Shortly before death it was found that the cancer had spread (metastasis) to their liver, bones and brain. They eventually suffered from multiple-organ failure. Considering the underlying cause alone, potentially understates the importance of these other health conditions that played a role in causing the death.
A doctor would use their knowledge of the deceased person as their patient, from medical records, or from next of kin to record each of these health events on the death certificate (Figure 1.1). These events are recorded as either the underlying cause, a direct cause (such as a complication) or a contributory cause (such as a significant condition that contributed to the death).
In this example, the underlying cause would be lung cancer. The direct causes were multiple-organ failure, which was a consequence of the development of metastasis (secondary cancer). The hypertension, diabetes and history of smoking were considered by the doctor to be significant contributors to the death (Figure 1.1).
When asking what caused this person’s death, it would be valid to give a range of answers, depending on what is meant by this question and the lens through which causes of death are examined.
Figure 1.1: Example death certificate
Four in 5 deaths involve more than one cause
While some people die from a single, isolated cause (for example, brain cancer), many people die after long periods of illness while experiencing multiple health conditions, or in a state of frailty and old age.
In 2022, 191,000 deaths were registered in Australia. Of these deaths, 4 in 5 had more than one cause recorded and almost one-quarter of deaths had 5 or more causes recorded. The average number of causes recorded per death generally increased with age and has been slowly increasing over time.
Leading causes of death differ depending on the question asked
The leading (most common) causes of death in Australia differ depending on whether the assessment is based on the multiple causes involved in the death, the underlying cause only, the direct causes or the contributory causes.
The 5 most common conditions involved in deaths of Australians in 2022 were coronary heart disease (CHD) (in 20% of deaths), dementia (18%), hypertension (12%), cerebrovascular diseases (11%) and diabetes (11%) (Figure 1.2).
Considering only the underlying cause, the most common causes were also CHD (in 10% of deaths) and dementia (9%). This was followed by cerebrovascular diseases, COVID-19 and lung cancer (each responsible for 5% of deaths).
The most common direct causes of death reflected conditions related to the underlying cause and included lower respiratory infections (in 8% of deaths), cardiac or respiratory arrest (6%), sepsis (6%), pneumonitis (4%) and hypertension (4%).
The most common contributory causes typically reflected chronic diseases and risk factor-related health conditions and included hypertension (contributing to 8% of deaths), diabetes (7%), coronary heart disease (6%), dementia (6%), and atrial fibrillation (5%).
Figure 1.2: Most common causes of death, by cause type, per cent of deaths, 2022
Note: Most common causes of death are based on the cause list for this report, see Technical notes: Classification of health conditions.
Source: AIHW National Mortality Database; Table S4.1.
Why is looking at multiple causes of death important?
When looking at what Australians die from, understanding the underlying cause of death is important to develop health programs and policies and for monitoring population health. However, death typically results from the interplay between multiple health conditions. Focusing solely on the underlying cause can underestimate the impact of other health conditions on a person’s death. Using a multiple cause approach provides a more complete picture of the health status of Australians. This approach can inform policy and prevention, for example, by:
- highlighting the involvement of potentially preventable complications of the underlying cause to inform strategies to minimise their occurrence.
- showing the contribution of preventable causes and modifiable risk factor-related conditions to provide additional focus for prevention strategies.
For example, when using all of the causes reported on Australian death certificates, coronary heart disease (the leading underlying cause of death), is shown to be involved in twice as many deaths as indicated by the underlying cause alone. Sepsis, a potentially preventable condition, does not feature as an underlying cause of death but was the third most common direct cause of death in 2022. Depressive disorders, hypertension, and alcohol use disorders were factors involved in death at rates 58, 35 and 10 times respectively, more than when looking only at the underlying cause.
What Australians die from differs by age and sex
Using the multiple cause approach, coronary heart disease was the most common cause of death for males in 2022, recorded in 24% of deaths. Dementia was the most common cause involved in female deaths, recorded in 23% of deaths. The most common underlying causes were also coronary heart disease in males and dementia in females, responsible for 11% and 12% of male and female deaths, respectively.
The most common direct causes of death were similar for males and females: lower respiratory infections (9% and 7%, respectively), cardiac/respiratory arrest (6% and 7% respectively) and sepsis (6% each). The most common contributory causes for males were diabetes (8%), coronary heart disease (8%) and hypertension (8%), and for females were hypertension (9%), dementia (7%) and diabetes (7%). Substance use disorders (alcohol, tobacco, other drugs) were common contributory causes for males, while musculoskeletal conditions (osteoporosis and osteoarthritis) were common contributory causes for females.
The most common causes of death also differed by age group: external causes were more common in people aged less than 54 and chronic diseases more common in people 55 and older. Direct causes of death for those aged 0–54 were more likely to be complications of external causes of death such as injury and poisoning. For those aged 55 and over, direct causes reflected complications of chronic diseases (such as infections, cardiac arrest, and respiratory failure) and other conditions experienced in the end stages of life (such as frailty).
Old age-related causes such as senility and frailty were common causes of death (underlying and direct) among centenarians (persons aged 100 years or over). Senility (old age) was reported in 17%, and frailty in 14%, of deaths of centenarians in 2022.
The most common causes contributing to deaths at ages 0–54 years included substance use disorders, depression, history of self-harm, and psychosocial factors such as those related to support systems and intimate partners. Chronic diseases emerged as common contributory causes from age 55 upwards with diabetes being the leading contributor between the ages of 55 and 84. This pattern is consistent with what we see for common underlying causes at these ages; that is, deaths at younger ages are due mainly to external causes, and deaths in the older ages due to chronic diseases.
Tobacco use is the leading risk factor causing death
Another way to look at what Australians die from is to examine health-related risk factors that contribute to death. Based on the latest burden of disease estimates for risk factors, tobacco use was the risk factor responsible for the most deaths, equivalent to 13% of all deaths in Australia in 2018 (AIHW 2021). This was followed by high blood pressure, overweight (including obesity) and dietary risks. Together, 44% of all deaths in 2018 were attributable to these 4 risk factors.
Psychosocial factors involved in death
Death is not wholly attributable to disease, injury, or health-related risk factors (such as smoking). It is well established that non-medical factors, such as social determinants, play a role in a person’s life and death (WHO 2024; AIHW 2022). Through an initiative of the Australian Bureau of Statistics, when available, these factors are now recorded together with a person’s other cause of death information. In this report, factors are presented for coroner-certified deaths only, and are described as psychosocial factors. In 2022, 4,007 deaths involved at least 1 psychosocial factor. The psychosocial factors most commonly involved in death in 2022 were issues related to support systems (in 25% of deaths), issues related to intimate partners (24%), suicide ideation (23%) and personal history of self-harm (21%).