EXPLANATORY NOTES


INTRODUCTION

1 This publication contains summary information on causes of death for all doctor certified deaths for Australia.

2 In order to complete a death registration, the death must be certified by either a doctor using the Medical Certificate of Cause of Death, or by a coroner. Approximately 80-90% of deaths each year are certified by a doctor. The remainder are reported to a coroner. Although there is variation in what constitutes a death that is reportable to a coroner across jurisdictions, they are generally reported in circumstances such as:

• Where the person died unexpectedly and the cause of death is unknown;
• Where the person died in a violent or unnatural manner;
• Where the person died during or as a result of an anaesthetic;
• Where the person was 'held in care' or in custody immediately before they died; and
• Where the identity of the person who has died is unknown.

3 Reportable deaths which were certified by a coroner will be included in Causes of Death, Australia (cat. no. 3303.0) to be released in March 2009. This publication will present causes of death for all deaths in 2007, whether certified by a doctor or coroner.

4 All coroner certified deaths registered after 1 January 2007 will be subject to a revision process. This is a change from previous years where all ABS Cause of death processing for a particular reference period was finalised approximately 13 months after the end of the reference period. Where insufficient information was available to code a cause of death (e.g. a coroner certified death was yet to be finalised by the Coroner), less specific ICD codes were assigned as required by the ICD coding rules. The revision process will enable the use of additional information relating to coroner certified deaths as it becomes available over time resulting in increased specificity of the assigned ICD-10 codes.

5 The full Causes of Death publication relating to the 2007 Causes of Death, Australia (cat. no. 3303.0) will be published in Mar 2009. Following that release, Causes of death for 2007 coroner certified deaths will be updated as more information becomes available to the ABS. Revised data for 2007 will be published both on a year registration basis and a year of occurrence basis in the 2008 Causes of death publication, due to be released in Mar 2010 and again in the publication relating to the 2009 collection due for release in 2011. Revisions will only impact on coroner certified deaths, as further information becomes available to the ABS about the causes of these deaths.

6 The data presented in this publication are also included in a series of spreadsheets that are available on the ABS website. Any references to tables in the Explanatory Notes also refers to these spreadsheets.

7 A glossary is provided in the Explanatory Notes tab detailing definitions of terminology used.


SCOPE AND COVERAGE

8 The statistics in this publication relate to the number of doctor certified deaths that were registered, not those which actually occurred, in the years shown.


Scope of causes of death statistics

9 The ABS causes of death statistics collection includes all deaths that occurred and were registered in Australia, including deaths of persons whose usual residence is overseas. Deaths of Australian residents that occurred outside Australia may be registered by individual Registrars, but are not included in ABS deaths or causes of death statistics.

10 The scope of the statistics includes:

• All deaths being registered for the first time.
• Deaths in Australia of temporary visitors to Australia.
• Deaths occurring within Australian Territorial waters.
• Deaths occurring in Australian Antarctic Territories or other external territories (excluding Norfolk Island).
• Deaths occurring in transit (i.e. on ships or planes) if registered in the State of "next port of call".
• Deaths of Australian Nationals overseas who were employed at Australian legations and consular offices (i.e. deaths of Australian diplomats while overseas) where able to be identified.
• Deaths that occurred in earlier reference periods that have not been previously registered (late registrations).

11 The scope of the statistics excludes:

• Still births/foetal deaths (these are accounted for in perinatal deaths).
• Repatriation of human remains of decedents whose death occurred overseas.
• Deaths overseas of foreign diplomatic staff (where these are able to be identified).
• Deaths occurring on Norfolk Island.

12 From the 2007 reference year, the scope of the collection is:

• all deaths registered in Australia for the reference year and are received by the ABS by the end of the March quarter of the subsequent year; and
• deaths registered prior to the reference year but not previously received from the Registrar nor included in any statistics reported for an earlier period.

13 As an example: records received by the ABS during the March quarter of 2008 which were initially registered in 2007 or prior (but not forwarded to the ABS until 2008) are assigned to the 2007 reference year. Any registrations relating to 2007 which are received by the ABS after the end of the March quarter are assigned to the 2008 reference year.


Coverage of Causes of Death Statistics

14 Ideally, for compiling annual time series, the number of events (deaths) should be recorded and reported as those occurring within a given reference period such as a calendar year. However, due to lags in registration of events and the subsequent delays in the provision of that information to the ABS, not all deaths are registered in the year that they occur. This ideal is unlikely to be met under the current legislation and registration business processes. Therefore, the occurrence event is approximated by addition of the event on a state/territory register of deaths. Also, some additions to the register can be delayed in being received by the ABS from the Registrar (processing or data transfer lags). In effect there are 3 dates attributable to each death registration:

• The date of occurrence (of the death),
• The date of registration or inclusion on the state/territory register,
• The month in which the registered event is lodged with the ABS.

15 About 4% to 6% of deaths occurring in one year are not registered until the following year or later. These are included with the count of registered deaths published for that year.


CLASSIFICATIONS

Socio-Demographic Classifications

16 A range of socio-demographic data is available for data in the causes of death collection. Standard classifications used in the presentation of causes of death statistics include age, sex, birthplace, marital status, multiple birth, occupation and Indigenous status. Statistical standards for social and demographic variables have been developed by the ABS, and are used to code these variables.


Geographic Classifications

Australian Standard Geographical Classification (ASGC)

17 The ASGC is a hierarchical classification system consisting of six interrelated classification structures. The ASGC provides a common framework of statistical geography and thereby enables the production of statistics which are comparable and can be spatially integrated. Cause of death statistics are coded to SLA and can be produced for aggregates of these, for example, Statistical Division, Statistical Sub-Division and State.

18 For further information about the ASGC refer to Australian Standard Geographical Classification (ASGC), Jul 2006 (cat. no. 1216.0).


Health Classifications

International Classification of Diseases (ICD)

19 The International Classification of Diseases (ICD) is the international standard classification for epidemiological purposes and is designed to promote international comparability in the collection, processing, classification, and presentation of causes of death statistics. The classification is used to classify diseases and causes of disease or injury as recorded on many types of medical records as well as death records. The ICD has been revised periodically to incorporate changes in the medical field. Currently ICD 10th revision (ICD-10) is used for Australian causes of death statistics

20 ICD-10 is a variable-axis classification meaning that the classification does not group diseases only based on anatomical sites, but also on the type of disease. Epidemiological data and statistical data is grouped according to:

• epidemic diseases
• constitutional or general diseases
• local diseases arranged by site
• developmental diseases
• injuries

21 For example, a systemic disease such as septicaemia is grouped with infectious diseases; a disease primarily affecting one body system, such as a myocardial infarction is grouped with circulatory diseases or a congenital condition such as spina bifida is grouped with congenital conditions.

22 For further information about the ICD refer to: WHO | International Classification of Diseases (ICD)

23 An online version of the ICD-10 can be found by following this link: http://www.who.int/classifications/icd/en/


DATA SOURCES

24 The registration of deaths is the responsibility of the individual state and territory Registrars of Births, Deaths and Marriages. As part of the registration process, information about the causes of death is supplied by either the medical practitioner certifying the death or by a coroner. For data presented in this publication, only deaths certified by a medical practitioner are included. Coroner certified deaths for 2007 will be published in Causes of Death, Australia (cat. no. 3303.0) which will be released in March 2009.

25 Other information about the deceased is supplied by a relative or other person acquainted with the deceased, or by an official of the institution where the death occurred. This information is provided to the Australian Bureau of Statistics (ABS) by individual Registrars for coding and compilation into aggregate statistics shown in this publication. Further information regarding causes of death data sources can be obtained from:

3317.0.55.001 - Information Paper: External Causes of Death, Data Quality, 2005
3317.0.55.002 - Information Paper: ABS Causes of Death Statistics: Concepts, Sources, and Methods, 2006

MORTALITY CODING

26 ICD-10 was adopted for Australian use for deaths registered from 1 January 1999. However, to identify changes between the ninth and tenth revisions, deaths for 1997 and 1998 were coded to both revisions. See Appendix 1 for concordances.

27 The extensive nature of the ICD enables classification of causes of death at various levels of detail. For the purpose of this publication, data is presented according to the ICD at the chapter level, with further disaggregation for major causes of death.

28 To enable the reader to see the relationship between the various summary classifications used in this publication, all tables show in brackets the ICD codes which constitute the causes of death covered.


Updates to ICD-10

29 The Updating and Revision Committee (URC), a WHO advisory group on updates to ICD-10, maintains the cumulative and annual lists of approved updates to the ICD-10 classification. The updates to ICD-10 are of numerous types including addition and deletion of codes, changes to coding instructions and modification and clarification of terms.

30 The cumulative list of ICD-10 updates can be found by following this link : http://www.who.int/classifications/icd/icd10updates/en/

Acquired Immune Deficiency Syndrome (AIDS)

31 As ICD-9 did not directly accommodate the coding of Acquired Immune Deficiency Syndrome (AIDS) and AIDS-related deaths, cases where AIDS was the underlying cause were coded to ICD-9 deficiency of cell-mediated immunity (279.1), from 1988 to 1995. In 1996, ABS adopted ICD-9 Clinically Modified (CM) for coding of AIDS and AIDS-related deaths. Hence, for 1996 to 1998, all AIDS-related deaths (i.e. deaths where AIDS was mentioned in any place on the death certificate) were coded to HIV infection (042-044). ICD-10 adopted from 1999 allows for the coding of AIDS and AIDS-related deaths (B20-B24).


STATE AND TERRITORY DATA

32 Causes of death statistics for states and territories in this publication have been compiled in respect of the state or territory of usual residence of the deceased, regardless of where in Australia the death occurred and was registered. The state or territory of usual residence for a perinatal death is determined by the state or territory of usual residence of the mother.

33 Statistics compiled on a state or territory of registration basis are available on request.


DATA QUALITY

34 In compiling causes of death statistics, the ABS employs a variety of measures to improve quality, which include:

• providing certifiers with certification booklets for guidance in reporting cases of death on medical certificates; and
• editing checks at the individual and aggregate levels.

35 The ABS implemented a new version of the automated mortality coding software for 2006 data. The same version of the software has been used for processing the 2007 data.

36 The quality of causes of death coding can be affected by changes in the way information is reported by certifiers.


Perinatal Deaths (P00-P96)

37 There is some variability over time across a range of the perinatal death categories and where the numbers are small, caution should be applied in drawing inferences about change over time.


Dementia

38 Since 2006, there has been a significant increase in the number of deaths coded to Dementia (F01-F03). Updates to the coding instructions in ICD-10 has resulted in the assignment of some deaths shifting from Cerebrovascular diseases (ICD-10 codes I60-I69) to Vascular Dementia (ICD-10 code F01). In addition changes to the Veterans’ Entitlements Act 1986 and Military Rehabilitation and Compensation Act 2004, and a subsequent promotional campaign targeted at health professionals, now allow for death from vascular dementia of veterans or members of the defence forces to be related to relevant service. No changes to ABS coding practices were made with regard to 2007 data which would impact on the number of deaths coded as Dementia.


SPECIFIC ISSUES FOR 2007 DATA

39 A number of issues should be taken into account by users when analysing the 2007 doctor certified causes of death data.

40 The number of doctor certified deaths due to both C78 Secondary malignant neoplasm of respiratory and digestive organs and C79 Secondary malignant neoplasm of other sites have decreased substantially from 2006 to 2007. In 2007 an analysis of these codes was undertaken as secondary cancers should rarely be the underlying cause of death. Improved coding and editing practices were instigated for 2007 to ensure correct assignment of a more appropriate primary neoplasm code.

41 In 2007, Chronic Obstructive Airways disease (COAD) increased for the first time since 2003. This increase is largely due to an improvement in coding practices. It was noted that in some jurisdictions the practice is to provide the term Chronic Airways Limitation instead of COAD. Investigations undertaken during coding supported this finding. All records with the term Chronic Airways Limitation now have a code from J44 assigned and this practice will continue in future years.


CONFIDENTIALISATION OF DATA

42 From 2007 data cells with values between 1 and 4 have been randomly assigned to protect confidentiality. As a result some totals will not equal the sum of their components.


EFFECTS OF ROUNDING

43 Where figures have been rounded, discrepancies may occur between totals and sums of the component items.


ACKNOWLEDGEMENT

44 The ABS publications draw extensively on information provided freely by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated: without it, the wide range of statistics published by the ABS would not be available.


RELATED PRODUCTS

45 Other ABS publications which may be of interest are outlined below. Please note, older publications may no longer be available through ABS bookshops but are available through ABS libraries. All publications released from 1998 onwards are available on the ABS website: https://www.abs.gov.au

ABS Directions in Aboriginal and Torres Strait Islander Statistics, Jun 2007, cat. no. 4700.0
Australian Demographic Statistics, cat no. 3101.0
Australian Social Trends, cat. no. 4102.0
Births, Australia, cat. no. 3301.0
Causes of Deaths, Australia: Summary Tables, 2007, cat. no. 3303.0.55.001
Causes of Infant and Child Deaths, Australia, 1982-96, cat. no. 4398.0
Deaths, Australia, cat. no. 3302.0
Deaths due to Diseases and Cancers of the Respiratory System, Australia, 1979-1994, cat. no. 3314.0
Deaths From External Causes, Australia - 1998 to 2002, cat. no. 3320.0
Demography Working Paper 2004/3 - Calculating Experimental Life Tables for Use in Population Estimates and Projections of Aboriginal and Torres Strait Islander Australians, 1991 to 2001, cat. no. 3106.0.55.003
Drug Induced Deaths, Australia, 1991-2001, cat. no. 3321.0.55.001
Experimental Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 1991 to 2009, cat. no. 3238.0
Information Paper: External Causes of Death, Data Quality, 2005, cat. no. 3317.0.55.001
Information Paper: ABS Causes of Death Statistics: Concepts, Sources, and Methods, 2006, cat.no.3317.0.55.002
Mortality Atlas, Australia, 1997 to 2000, cat. no. 3318.0
Multiple Cause of Death Analysis, 1997-2001, cat. no. 3319.0.55.001
Population Projections, Australia, 2006 to 2101, cat. no. 3222.0
Recent Developments in the Collection of Aboriginal and Torres Strait Islander Health and Welfare Statistics, 2005, cat. no. 4704.0.55.001
Suicides, Australia, 2005, cat. no. 3309.0
Suicides: Recent Trends, Australia, 1993 to 2003, cat. no. 3309.0.55.001
The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples, 2008, cat. no. 4704.0
Trends in Mortality by Causes of Death in Australia, the States and Territories During 1971-92, and in the Regions during 1991-1992, 1971-92, cat. no.3313.0

46 ABS products and publications are available free of charge from the ABS website <https://www.abs.gov.au>. Click on Statistics to gain access to the full range of ABS statistical and reference information. For details on products scheduled for release in the coming week, click on the Future Releases link on the ABS homepage.


ADDITIONAL STATISTICS AVAILABLE

47 As well as the statistics included in this and related products, additional information is available from the ABS web site at <https://www.abs.gov.au> by accessing the topics listed at Themes>People. The ABS may also have other relevant data available on request. Inquiries should be made to the National Information and Referral Service on 1300 135 070 or by sending an email to client.services@abs.gov.au.