Calculating mortality rates

All deaths analysis in this report are based on the underlying cause of death, that is, the disease or injury that initiated the train of events leading directly to death, or the circumstances of the accident or violence that produced the fatal injury. Causes of death are coded by the ABS to the International Statistical Classification of Diseases and Related Health Problems (ICD). Deaths where the underlying cause of death information was missing were excluded from this analysis.

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.

Deaths data presented in this analysis are based on year of occurrence. These may differ from deaths data presented in other Australian Institute of Health and Welfare (AIHW) publications that are based on year of registration.

‘Age-standardised mortality rate per 100,000 person-years’ is the hypothetical number of deaths per 100,000 people in a population that would have been observed if the population groups had the same age structure. The population standard used was the 2001 Australian Standard Population.

The definition of potentially avoidable deaths (PADs) is outlined in the Metadata Online Registry (METEOR) specification: National Healthcare Agreement: PI 16-Potentially avoidable deaths, 2022. The rate of PADs in Australia is used as an indicator of the health system's effectiveness – they are classified using nationally agreed definitions. They do not indicate that these deaths have individually been assessed as avoidable.

Deaths due to suicide were identified by an underlying cause of death of X60-X84 intentional self-harm or Y87 sequelae of intentional self-harm, assault and events of undetermined intent.