What do Australians die from?

Understanding what Australians die from is complex and can vary depending on the purpose of the information. From a public health perspective, identifying the conditions responsible for initiating the death (the underlying cause) is crucial to informing preventive health programs. Assessing the other cause types (multiple, direct, and contributory) can provide additional insight into, for example potentially preventable conditions that ultimately end a person’s life, or which causes contribute to high proportions of deaths. This information is less visible when using only the underlying cause perspective. 

Figure 4.1 shows for each cause type (multiple, underlying, direct and contributory), the most common causes in 2022.

Figure 4.1: Most common causes of death, by cause type, 2022

Notes 

1. Deaths registered in 2022 are based on the preliminary version and are subject to further revision by the Australian Bureau of Statistics.
2. Each death can involve one or more multiple, direct or contributory cause. As a result, the total percentage by a cause type can be greater than 100.

Source: AIHW National Mortality Database; Table S4.1.

Most commonly reported causes of death are coronary heart disease, dementia and hypertension

Multiple causes reflect how often the health condition is involved in causing death. In 2022, the 20 causes most commonly involved in death included a mix of chronic conditions, infectious diseases, risk factor-related causes and non-specific causes.

The 5 most common conditions involved in death in 2022 were:

• coronary heart disease (CHD) (involved in 20% of deaths)
• dementia (18%)
• hypertension (12%)
• cerebrovascular diseases (11.5%)
• diabetes (11.4%) (Figure 4.1). 

Coronary heart disease and dementia are the most common underlying causes

Understanding the underlying causes provides fundamental public health information for monitoring and improving the health of populations, and is the standard used for international and other comparisons. 

When looking at the underlying cause of death, the most common were coronary heart disease in 10% and dementia in 9% of deaths, followed by cerebrovascular diseases (5.2%), COVID-19 (5.2%) and lung cancer (4.7%). The leading 20 underlying causes also included other cancers, falls and suicide (Figure 4.1).

Lower respiratory infections are the most common direct cause of death 

The most common direct causes differed substantially from the underlying causes. 

The most common direct causes of death in 2022 were: 

• lower respiratory infections (in 8% of deaths)
• cardiac or respiratory arrest (6.5%) 
• sepsis (6.2%)
• pneumonitis (4.4%)
• hypertension (4.0%) (Figure 4.1). 

At the end of life, there is increased risk of lower respiratory complications, such as pneumonia, particularly for people with coronary heart disease, dementia and COVID-19 (ABS 2023; Dementia Australia 2018). 

To improve treatment and interventions at the end of life, it is important to identify direct causes which are potentially preventable or treatable, or could be minimised (for example, sepsis and pneumonitis). Consequences of medical and surgical care (for example, postoperative complications) were direct causes in 2% of deaths. These conditions reflect complications that can arise from care in the hospital setting or later as postoperative complications (ANZCA 2023; WHO 2023; ACSQHC 2018). With more than half of all deaths in Australia occurring in a hospital or medical setting (ABS 2021), understanding these outcomes is of particular importance for improving health care (ACSQHC 2022; ABS 2021; ACSQHC 2018; The George Institute 2017). Data on direct causes of death can be used to harness this information and inform specific monitoring activities.

Hypertension is the cause that most commonly contributes to death 

Around two-thirds of Australians (almost 16.5 million people) are estimated to have 2 or more long-term health conditions (referred to as multimorbidity) (ABS 2022). The impact of multimorbidity is mirrored in causes of death data with long-term conditions featuring as the most common contributors to death.

The leading specific contributory causes of death in Australia in 2022 were:

• hypertension (contributing to 8% of deaths)
• diabetes (7%)
• coronary heart disease (6.4%)
• dementia (5.9%)
• atrial fibrillation (5.4%) (Figure 4.1).

Additionally, high cholesterol was a contributing cause in 2% of deaths, depressive disorders in 2%, alcohol use disorders in 1% and osteoporosis in 1% of deaths. 

Many of these conditions are preventable or treatable, and their involvement as contributory causes of death is less visible in statistics based on the underlying cause.

Total involvement of conditions in death

Some causes featured as underlying, direct, and contributory causes. Coronary heart disease, dementia, cerebrovascular diseases, chronic kidney disease and atrial fibrillation featured among the 20 most common conditions across all cause types. This would suggest that these conditions frequently play multiple roles in causing death. 

In particular, the approach using multiple causes shows that using an underlying cause approach in isolation can underestimate the involvement of certain conditions in causing death. For example, in 2022:

• coronary heart disease was the leading underlying cause for almost 1 in 10 deaths but was involved in 1 in 5 deaths when multiple causes were considered.
• the proportion of deaths involving dementia and cerebrovascular disease was twice as high as the proportion of deaths identifying them as the underlying cause.
• diabetes was involved in 4 times as many deaths as were shown using the underlying cause. 

On the other hand, the conditions most involved in causing death are often not revealed by looking at the underlying cause only. For example, hypertension, (specified) heart failure and sepsis were among the most commonly recorded causes, but were not among the leading underlying causes.