Novel insights into the underlying, contributing, and direct causes of death in Australia

Coronary heart disease (CHD) was involved in 1 in 5 deaths in 2022 when using all of the information included on the medical death certificate, according to a new Australian Institute of Health and Welfare (AIHW) release revealing what Australians are most likely to die from.

What do Australians die from? highlights the most common causes involved in the 191,000 registered deaths in Australia in 2022. It uses all health conditions recorded on the death certificate to provide new insights into the health conditions causing and contributing to a person’s death, highlighting the interplay of multiple diseases and the role played by each. Risk factors and psychosocial contexts involved in death are also explored.

“Understanding what Australians die from is complex and the answer can vary, depending on how we assess the conditions involved,” AIHW spokesperson Michelle Gourley said.

“Traditionally, statistics about how people die are based primarily on the initiating or ‘underlying’ cause of death, but death certificates also 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 (heart attack). Other conditions that significantly contributed to the death such as hypertension, diabetes, alcohol use disorders, COVID-19 and other contextual factors may also be recorded on the death certificate.”

The report shows that 4 in 5 deaths involved more than one cause and almost one-quarter of deaths had 5 or more causes recorded.

While CHD was the most common underlying cause of death of Australians in 2022 (responsible for 1 in 10 deaths), it was involved in many more deaths (1 in 5) when considering all of the information included on the death certificates. Dementia (18%), hypertension (12%), cerebrovascular diseases and diabetes (both 11%) were other common conditions involved in deaths.

The most common conditions contributing to death typically reflect chronic diseases and risk factor-related health conditions and included hypertension (8%), diabetes (7%) and CHD (6%). Substance use disorders such as alcohol (2.0%), tobacco (1.3%) and other drugs (1.6%) were more common contributory conditions for males, while dementia (7%) and musculoskeletal conditions such as osteoporosis (1.9%) and osteoarthritis (1.5%) were more common contributory conditions for females.

The most common direct causes of death (those that ultimately end a person’s life) were lower respiratory infections (8%), cardiac/respiratory arrest (7%) and sepsis (6%).

What Australians die from varies greatly by age. For people aged 15 to 54, external causes such as suicide, road traffic injuries and accidental poisoning were common underlying causes of death. The associated complications from these causes (e.g. asphyxiation, toxic effect of substances and drugs) were reflected in common direct causes of death. Substance use disorders, depressive disorders, and psychosocial factors (such as history of self-harm, intimate partner issues and support system factors) featured prominently as common conditions contributing to deaths at these ages.

For those aged 55 and over, chronic diseases such as coronary heart disease, dementia and cancer were common underlying causes of death. Direct causes of death reflected complications of these chronic diseases (such as infections, cardiac arrest, and respiratory failure) and other conditions experienced in the end stages of life (such as frailty). Diabetes, hypertension, chronic obstructive pulmonary disease (COPD) and dementia were common conditions contributing to deaths at these older ages.

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. 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 in relation to developing strategies and interventions to reduce the impact of diseases and promote better health.”

Michelle Gourley, AIHW spokesperson