Codes and classifications

International Statistical Classification of Diseases and Related Health Problems

The International Statistical Classification of Diseases (ICD), which was developed by the World Health Organization, is the international standard for coding morbidity and mortality statistics. It was designed to promote international comparability in collecting, processing, classifying and presenting these statistics. The ICD is periodically reviewed to reflect changes in clinical and research settings.

Coding for deaths due to suicide

For Suicide & self-harm monitoring, deaths since 1964 (included in the National Mortality Database (NMD)) classified as 'intentional self-harm' according to the relevant revisions of the ICD classification were included:

For deaths prior to 1964, please see General Record of Incidence of Mortality (GRIM) books GRIM 2017 Intentional self-harm (suicide) X60–X84, Y87.0 for ICD versions and codes used.

Coding for intentional self-harm hospitalisations

Diagnosis, intervention and external cause data are reported to the National Hospital Morbidity Database (NHMD) by all states and territories using the International Statistical Classification of Diseases and Related Health Problems, 10th revision, Australian Modification (ICD-10-AM) and the Australian Classification of Health Interventions (ACHI). The Australian Coding Standards (ACS) are designed to be used in conjunction with the ICD-10-AM and ACHI to support sound coding convention.

The hospital separations reported were coded according to the applicable ICD-10-AM edition for the following years:

• 2008–09 to 2009–10: ICD-10-AM Sixth Edition
• 2010–11 to 2012–13: ICD-10-AM Seventh Edition
• 2013–14 to 2014–15: ICD-10-AM Eighth Edition
• 2015–16 to 2016–17: ICD-10-AM Ninth Edition
• 2017–18 to 2018–19: ICD-10-AM Tenth Edition
• 2019–20 to 2021–22: ICD-10-AM Eleventh Edition
• 2022–23 to 2024–25: ICD-10-AM Twelfth Edition.

Records that satisfied the following criteria were included:

• a principal diagnosis in the ICD-10-AM range S00–T75, T79 (Injury, poisoning and certain other consequences of external causes)
• the first reported external cause code in the record in the ICD-10-AM range X60–X84, Y87.0 (external causes of morbidity).

Excluded from the criteria are:

• separations for which the care type was reported as Newborn (without qualified days), and records for Hospital boarders or Posthumous organ procurement
• separations with a mode of admission of 'transfer from another hospital'
• separations with reported ICD-10-AM code Z50 (Care involving the use of rehabilitation procedures) in additional diagnosis.

Changes to the Australian Coding Standard for Rehabilitation in ICD-10-AM (Ninth Edition), means that the ‘reason’ for rehabilitation (codes S00–T98 Injury, poisoning and certain other consequences of external causes) will be assigned the principal diagnosis and the rehabilitation code (Z50) will be sequenced as the additional diagnosis. This change results in an increase in the number of separations in principal diagnoses with codes from S00–T98 from 1 July 2015 onwards. In order to reflect the number of injury separations where the primary clinical intent is acute care and not rehabilitation, records with Z50 (Care involving the use of rehabilitation procedures) in principal diagnosis or additional diagnosis for all years are excluded in the data set before and after the coding change.

Intentional self-harm hospitalisations reported in Suicide & self-harm monitoring may differ from other publications. The differences are small and may reflect differences in the inclusion criteria (for example, Y87.0 included here) and/or exclusion criteria. Data may also be subject to periodic updates occurring after the original publication date.