What causes death in Australia?
Understanding what causes death can be more complicated than it sounds and can vary depending on what we want to know. This section of the report looks at the common causes of death in Australia, and the role they play including:
- the diseases or causes 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)
- all of the causes involved in a death (multiple causes).
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.
It is important to note that each death can have more than one multiple, direct, or contributory cause.
Some conditions are more likely to be reported as an underlying, direct or contributory cause
Health conditions can play different roles in causing death. Some conditions are more likely to be reported as either the underlying, direct or contributory cause of death (Table S8.3)
Cancer was most likely to be mentioned on a death certificate as an underlying cause of death (71% of mentions).
Direct causes of death are often complications of the underlying cause and are experienced at the end of life. We see this reflected through:
- injuries recorded as a direct cause 88% of times they are mentioned
- infections recorded as a direct cause 65% of the times they are mentioned
Contributory causes can reflect chronic diseases, risk factor-related conditions, or psychosocial factors. Examples of conditions which are more likely to be mentioned as contributing to death, but not be in the chain of events leading, to death include:
- mental and behavioural disorders (73% of mentions are as a contributory cause)
- musculoskeletal conditions (71% of mentions are as a contributory cause)
Most common causes involved in deaths in Australia
In 2024, the 20 causes most commonly involved in death overall (multiple causes) included a mix of chronic conditions, infectious diseases, risk factor-related causes and non-specific causes (Table S8.4).
Using the multiple cause of death approach highlights that when using only the underlying cause for death statistics, it may underestimate the overall impact of certain conditions. For example, diabetes and chronic kidney disease are involved in three and six times as many deaths overall than as an underlying cause of death. Other conditions such as coronary heart disease, cerebrovascular disease and COPD were involved in twice as many deaths than when considering the underlying cause alone (Figure 8.1).
Figure 8.1: Most common causes of death, by cause type, 2024
The types of conditions and the role they play differ by sex, and across the lifespan.
Notes:
- COPD Chronic Obstructive Pulmonary Disease
- The year refers to year of registration of death. Deaths registered in 2024 are based on the preliminary version and are subject to further revision by the Australian Bureau of Statistics (ABS).
- Cause groups and specific causes are based on the cause list used for reporting on multiple causes of death as described in the Technical notes: Classifying causes of death.
Source: AIHW National Mortality Database; Tables S8.4 & S8.5.
Many of the types of multiple causes are similar for males and females, with different rank and percentage contributions (Table S8.4). There are some notable differences for contributory causes. In 2024:
- substance use disorders (alcohol, tobacco, other drugs) were among the most common contributory causes for males
- musculoskeletal conditions (osteoporosis and osteoarthritis) were common contributory causes for females (Table S8.4).
Differences are seen across the lifespan in the types of deaths and the role they play. For younger Australians:
- external causes (such as suicide, road traffic accidents) and substance use disorders were the most common causes overall
- the direct causes of death reflect common consequences and outcomes of those external events (such as injuries, and toxic effects of substances & drugs)
- mental and behavioural conditions and psychosocial factors (such as issues relating to intimate partners or support systems) are the most common contributory causes (Figure 8.1).
From ages 45–64 a shift begins in the most common causes of death:
- chronic diseases such as coronary heart disease, liver disease and diabetes become the most common causes overall
- mental and behavioural conditions (such as drug and alcohol use, depression and anxiety) remain common contributory causes (Figure 8.1).
From ages 65–94, the most commonly recorded causes involved in, and contributing to, death were chronic diseases (Figure 8.1). The most common direct causes reflect late effects and end-stage outcomes of those chronic diseases, such as: infections, secondary cancer sites (metastasis), or cardiac and/or respiratory failure.
For the oldest Australians, 95 years and older:
- dementia was the most common cause involved in death overall
- frailty and senility were among the most often reported direct and contributory causes (Figure 8.1).