Heart, stroke and vascular disease: Australian facts

Australia uses the International Statistical Classification of Diseases and Related Health Conditions to code causes of death (WHO 2019).

In this report, deaths between 1981 and 1996 were coded using the Ninth Revision (ICD-9), and deaths from 1997 using the Tenth Revision (ICD-10) (Table 1).

Table 1: International Classification of Disease (ICD) codes

Source: WHO 2019.

The change in classification between ICD-9 and ICD-10 has resulted in a break in the underlying cause of death series between 1996 and 1997. Where available, comparability factors been applied to allow underlying cause of death data to be compared across this time period (Table 2).

Table 2: Comparability factors for the ICD–9 to ICD–10 transition

(a) Uses the comparability factor for Diseases of arteries, arterioles and capillaries (ICD–10 codes I70–I79).

(b) Uses the comparability factor for Congenital malformations of the circulatory system (ICD–10 codes Q20–Q28).

Source: ABS 2009.

For hospital diagnoses and procedures, a classification modified for Australia is used. Hospital data to 1997–98 used the ICD-9-CM (International Classification of Diseases and Related Health Conditions, Ninth Revision, Clinical Modification) classification. After 1997–98, the ICD-10-AM classification (International Statistical Classification of Diseases and Related Health Conditions, Tenth Revision, Australian Modification) was used.

Diagnosis and procedure data for 2020–21 were reported to the NHMD using the 11th edition of the ICD-10-AM (ACCD 2018a), incorporating the Australian Classification of Health Interventions (ACHI) (ACCD 2018b) (Tables 3 and 4).

For emergency department diagnoses, a classification modified for Australia, the ICD-10-AM (11th Revision) shortlist was used (Table 3).

Table 3: ICD-9-CM and ICD-10-AM codes

Source: ACCD 2018a and IHACPA 2022.

Table 4: Australian Classification of Health Interventions (ACHI) codes

Source: ACCD 2018b.

Anatomical Therapeutic Chemical classification

Anatomical Therapeutic Chemical (ATC) codes are used in this report to classify medicines. This classification groups medicines according to the body organ or system they act upon, their therapeutic characteristics, and their chemical characteristics.

A list of the medicine groups included in this report is shown in Table 5.

More information on the ATC classification system can be found at the WHO Collaborating Centre for Drug Statistics Methodology.

Table 5: Anatomic Therapeutic Chemical medicine groups