The ABS sources information about deaths and their causes from the RBDMs in each state and territory. The ABS compiles these data and codes the causes of death to an international standard, called the International Statistical Classification of Diseases and Related Health Problems (ICD). Coding causes of death to an international standard enables the comparability of statistics over time and between countries.
The ICD is revised periodically and currently in its tenth revision (ICD-10). The ICD-10 has been used for Australian causes of death statistics since 1997 and comprises more than 14,000 causes of death and illness; analysis of groups of causes is therefore more manageable than individual causes.
The coding produces an underlying cause—the disease or condition which initiated the sequence of events resulting in death—and, for most deaths, associated causes (any other diseases or conditions that contributed to the death but were not the underlying cause).
Once coded, causes of death can be categorised into disease groupings. Disease groupings are useful for tabulating causes of death in a meaningful way and for examining patterns and trends by cause of death and other important population attributes.
A common method of grouping causes is by ICD chapters (see Table 1). The chapters are arranged according to the type of disease (for example, ‘Certain infectious or parasitic diseases’), the body system affected (for example, ‘Diseases of the circulatory system’) or the circumstance causing death (for example, ‘External causes of morbidity and mortality’, which include injury and poisoning).
For some public health purposes, information about causes of death needs to be more specific; coding causes of death enables identification of specific causes such as influenza, stroke or motor vehicle accident.
There are other methods of grouping diseases that are useful for public health purposes. For example, see Deaths in Australia.
Table 1: International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) chapters
||Certain infectious and parasitic diseases
||All diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
||Endocrine, nutritional and metabolic diseases
||Mental and behavioural disorders
||Diseases of the nervous system
||Diseases of the eye and adnexa
||Diseases of ear and mastoid process
||Diseases of the circulatory system
||Diseases of the respiratory system
||Diseases of the digestive system
||Diseases of the skin and subcutaneous tissue
||Diseases of the musculoskeletal system and connective tissue
||Diseases of the genitourinary system
||Pregnancy, childbirth and the puerperium
||Certain conditions originating in the perinatal period
||Congenital malformations, deformations and chromosomal abnormalities
||Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
||Injury, poisoning and certain other consequences of external causes
||External causes of morbidity and mortality
||Factors influencing health status and contact with health services
||Codes for special purposes (including COVID-19)