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AR-DRG cubes for 1997–98 to 2014–15

Australian Refined Diagnosis Related Groups (AR-DRGs) is an Australian admitted patient classification system which provides a clinically meaningful way of relating the number and type of patients treated in a hospital (that is, its casemix) to the resources required by the hospital. Each AR-DRG represents a class of patients with similar clinical conditions requiring similar hospital services. The classification categorises acute admitted patient episodes of care into groups with similar conditions and similar usage of hospital resources, using information in the hospital morbidity record such as the diagnoses, procedures and demographic characteristics of the patient.

The AR-DRG data cubes contain separations for which the care type was specifically reported as Acute, Newborn (for separations with at least one qualified day) or was not reported (see the Glossary). Where identifiable, other separation care types have been excluded.

Data source

The source of these data is the AIHW National Hospital Morbidity Database. Other data on the principal diagnoses and AR-DRGs of hospitalised patients is available in the Australian hospital statistics reports. Some data have been revised since previously published. For confidentiality, some data have been suppressed.


Data cubes will open in a new window.

The use of the different editions in the six data cubes means that data across years may not be exactly comparable.

The variables in the data cube are:

  • Year
  • Sex (Male, Female, Other/Not reported)
  • Age group (5 year groupings, i.e. <1, 1–4, 5–9, 10–14, ... 85+, Not reported)
  • Same day flag (Same day/Overnight)
  • AR-DRG

The measures (values) in the data cube are:

  • Total separations
  • Patient days
  • Average length of stay (ALOS)

Within the cubes, users can view the AR-DRG by using a pull-down menu and can work down from the Major Diagnostic Category (MDC) level to the surgical/medical/other partition of the MDC to the individual DRGs, as outlined below.

  • Major diagnostic category
  • Surgical/Medical/Other partition
  • DRG E01A

For example

  • MDC 04. Diseases and disorders of the respiratory system
  • Surgical
  • DRG E01A Major chest procedures with catastrophic complication or comorbidity

Users of the data cube are likely to require some familiarity with AR-DRGs and have access to the definitions manual. This data access system does not allow searching on key words for AR-DRG. Users will generally need to know what MDC the information they are looking for is in, to work down to more specific levels of detail.

Australian Refined Diagnosis Related Groups (AR-DRGs)

The AR-DRG classification is separated into 23 Major Diagnostic Categories (MDCs) and further categorised into medical, surgical and other groupings. AR-DRG assignment is also influenced by procedures, medical conditions and other factors that differentiate processes of care.

For further information on AR-DRGs refer to the Department of Health website.

Major Diagnostic Categories and the AR-DRG ranges covered by each
MDC MDC Description AR-DRG range
Pre-MDC Major procedures where the principal diagnosis may be associated with any MDC A01Z-A41Z
01. Diseases and disorders of the nervous system B01Z-B81B
02. Diseases and disorders of the eye C01Z-C63B
03. Diseases and disorders of the ear, nose, mouth and throat D01Z-D67Z
04. Diseases and disorders of the respiratory system E01A-E75C
05. Diseases and disorders of the circulatory system F01Z-F75C
06. Diseases and disorders of the digestive system G01A-G70B
07. Diseases and disorders of the hepatobiliary system and pancreas H01A-H64B
08. Diseases and disorders of the musculoskeletal system and connective tissue I01Z-I76C
09. Diseases and disorders of the skin, subcutaneous tissue and breast J01Z-J67B
10. Endocrine, nutritional and metabolic diseases and disorders K01Z-K64B
11. Diseases and disorders of the kidney and urinary tract L01A-L67C
12. Diseases and disorders of the male reproductive system M01Z-M64Z
13. Diseases and disorders of the female reproductive system N01Z-N62B
14. Pregnancy, childbirth and the puerperium O01A-O65B
15. Newborns and other neonates P01Z-P67D
16. Diseases and disorders of the blood and blood forming organs and immunological disorders Q01Z-Q62B
17. Neoplastic disorders (haematological and solid neoplasms) R01A-R64Z
18. Infectious and parasitic diseases S60Z-T64B
19. Mental diseases and disorders U40Z-U68Z
20. Alcohol/drug use and alcohol/drug induced organic mental disorders V60Z-V64Z
21. Injuries, poisoning and toxic effects of drugs W01Z-X64B
22. Burns Y01Z-Y62B
23. Factors influencing health status and other contacts with health services Z01A-Z65Z
Error-DRG Error DRGs 801Z-963Z

Abbreviations used in the AR-DRG cubes
Abbreviation Description
Adm Wt Admission weight
AMI Acute myocardial infarction
Cat Catastrophic
CC Complication or comorbidity
CDE Common duct exploration
D and C Dilation and curettage
ECMO Extracorporeal membrane oxygenation
ECT Electroconvulsive therapy
ERCP Endoscopic retrograde cholangiopancreatography
ESW Extracorporeal shock wave
HIV Human immunodeficiency virus
O.R. Operating room
TIA Transient ischaemic attack
URI Upper respiratory tract infection
W With
W/O Without

AR-DRG versions between 1997–98 and 2013–14

The AR-DRG classification is regularly updated to align with continual changes to medical or surgical practices and techniques, which are reflected in changes in the ICD-10-AM and ACHI coding systems. Table 1 shows the relevant ICD-10-AM editions and AR-DRG versions from 1998–99 to 2011–12. AR–DRG Classification, version 7.0, used for the 2013-14 year, was released in October 2012.

ICD-10-AM and AR-DRG versions, 1998–99 to 2013–14
Year ICD-10-AM edition Relevant AR-DRG version AR-DRG version reported in Australian hospital statistics
1998–99 First edition Version 4.1 Version 4.0/4.1
1999–2000 First edition Version 4.1 Version 4.2
2000–01 Second edition Version 4.2 Version 4.2
2001–02 Second edition Version 4.2 Version 4.2
2002–03 Third edition Version 5.0 Version 5.0
2003–04 Third edition Version 5.0 Version 5.0
2004–05 Fourth edition Version 5.1 Version 5.1
2005–06 Fourth edition Version 5.1 Version 5.1
2006–07 Fifth edition Version 5.2 Version 5.1
2007–08 Fifth edition Version 5.2 Version 5.1
2008–09 Sixth edition Version 6.0 Version 5.2
2009–10 Sixth edition Version 6.0 Version 5.2
2010–11 Seventh edition Version 6.0 Version 6.0
2011–12 Seventh edition Version 6.0x Version 6.0x

For further information regarding ICD-10-AM and ACHI classification systems refer to the Australian Consortium for Classification Development.

AR-DRG logic and definition changes may require the mapping of ICD-10-AM diagnosis and ACHI procedure codes between editions. 'Mapping' refers to the process of finding an 'equivalent' code between two editions (or classifications for the 1998–99 year) to enable data users to interpret data partly classified in one edition/classification and partly classified in another. This means that the data will not be completely comparable between years. Caution should therefore be exercised in comparing data between years.


In order to maintain confidentiality some data have been suppressed at the Diagnosis Related Group level if:

  • there is a potential risk of identifying an individual
  • there are fewer than three reporting units (hospitals or states/territories where the hospitals are not individually identified), or
  • there are three reporting units and one contributed more than 85% of the total separations, or
  • there are three or more reporting units and two contributed more than 90% of the total separations.

Data for the suppressed categories will not appear in the data cubes, but will be included in the surgical/medical/other partition, MDC, and grand totals. Thus, the sum of separation counts presented within a surgical/medical/other partition or MDC may not match the total.