Leading underlying causes of death by sex
Coronary heart disease is the leading underlying cause of death in Australia, followed by dementia including Alzheimer disease. Cerebrovascular disease (which includes stroke), lung cancer and chronic obstructive pulmonary disease (COPD) make up the top 5 leading underlying causes of death in Australia in 2018, for males and females of all ages combined.
Figure 3.1 below shows the number of male and female deaths contributing to the top 5 causes. The leading cause of death for males was coronary heart disease, accounting for 10,269 (13%) deaths. Dementia including Alzheimer disease was the leading cause of death for females, accounting for 8,973 (12%) deaths, followed by coronary heart disease (7,264; 10% of deaths). Cerebrovascular disease (which includes stroke), lung cancer and chronic obstructive pulmonary disease (COPD) make up the top 5 leading underlying causes of death in Australia in 2018 for males and females of all ages combined. For more leading causes of death by sex see Table S3.1.

Note: Leading causes of death are based on underlying causes of death and classified using an AIHW-modified version of Becker et al. 2006.
Source: AIHW National Mortality Database (Table S3.1).
Leading underlying causes of death by age
As well as differences by sex, the leading causes of death also vary by age. Chronic diseases feature more prominently among people aged 45 and over, while the leading causes of death among people aged 1–44 are external causes, such as accidents and suicides (Figure 3.2).
Among infants, perinatal and congenital conditions caused the most (80%) deaths.
Land transport accidents were the most common cause of death among children aged 1–14 (11%). Suicide was the leading cause of death among people aged 15–24 (37%), followed by land transport accidents (21%). For people aged 25–44, it was also suicide (22%), followed by accidental poisoning (13%).
Coronary heart disease was the leading cause of death for people aged 45–64, followed by lung cancer. For people aged 65–74, it was lung cancer followed by coronary heart disease. Dementia including Alzheimer disease was the second leading cause of death among people aged 75 and older, behind coronary heart disease.


Notes:
- ‘Other ill-defined causes’ include the following codes: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (ICD-10 codes R00–R99, excluding R95: Sudden infant death syndrome (SIDS)); Cardiac arrest, unspecified (I46.9); Respiratory failure of newborn (P28.5); Respiratory failure, unspecified (J96.9). AIHW General Record of Incidence of Mortality (GRIM) books are available for selected leading causes of death.
-
There were no suicide deaths in children under 5. The number of deaths of children attributed to suicide can be influenced by coronial reporting practices, see ABS 3303.0 – Causes of Death, Australia, 2011 (Explanatory Notes 92–95) for further information.
Source: AIHW National Mortality Database (Table S3.2).
Classifying causes of death
Leading underlying causes of death are determined by grouping specific causes of death and counting the number of deaths assigned to each cause group. Over 14,000 specific causes of illness, injury and death are presented in the International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10). These causes can be grouped in a way that is meaningful for public health purposes.
A common grouping is by ICD chapters which are broad categories arranged according to the type of disease, the body system affected by the disease or the circumstances causing death. Each chapter is further divided into blocks of related diseases. Australian cause of death data by ICD-10 chapters and selected causes of death are published in the AIHW General Record of Incidence of Mortality (GRIM) books.
For leading underlying cause of death analysis, information needs to be more specific than ICD chapters and blocks. There is no standard method for grouping causes, however, the AIHW follows the recommendations of the World Health Organization (WHO) (Becker et al. 2006) with minor modifications to suit the Australian context. This grouping is a mix of ICD chapters, blocks and specific diseases to maximise information, separate out ill-defined causes and highlight health priority areas.
The leading underlying causes of death presented here are classified using an AIHW-modified version of Becker et al.
Reference
Becker R, Silvi J, Ma Fat D, L’Hours A & Laurenti R 2006. A method for deriving leading causes of death. Bulletin of the World Health Organization 84:297–304.