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6 The registration of deaths is the responsibility of the eight individual state and territory Registrars of Births, Deaths and Marriages. As part of the registration process, information about the cause of death is supplied by the medical practitioner certifying the death or by a coroner. 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. The information is provided to the Australian Bureau of Statistics (ABS) by individual Registrars for coding and compilation into aggregate statistics. In addition, the ABS supplements this data with information from the National Coronial Information System (NCIS). The following diagram shows the process undertaken in producing cause of death statistics for Australia.
The diagram below outlines the Australian Cause of Death Statistics System. Each death is certified by either a doctor or coroner and the resultant information is provided to the Australian Bureau of Statistics (ABS) through the Registrar of Births, Deaths and Marriages in each state or territory. Information is also provided via the National Coronial Information System for those deaths certified by a coroner. The ABS processes, codes and validates this information, which is then provided in statistical outputs.
2017 scope and coverage
7 Ideally, for compiling annual time series, the number of deaths should be recorded and reported as those which occurred within a given reference period, such as a calendar year. However, there can be lags in the registration of deaths with the state or territory registries and so not all deaths are registered in the year that they occur. There may also be further delays to the ABS receiving notification of the death from the registries due to processing or data transfer lags. Therefore, every death record will have:
8 With exception to the statistics published by Year of Occurrence section (Data Cube 13), all deaths referred to in this publication relate to the number of deaths registered, not those which actually occurred, in the years shown.
Scope of Causes of Death statistics
9 The scope for each reference year of the death registrations includes:
10 From 2007 onwards, data for a particular reference year includes all deaths registered in Australia for the reference year that are received by the ABS by the end of the March quarter of the subsequent year. Death records received by the ABS during the March quarter of 2018 which were initially registered in 2017 (but for which registration was not fully completed until 2018) were assigned to the 2017 reference year. Any registrations relating to 2017 which were received by the ABS from April 2018 will be assigned to the 2018 reference year. Approximately 4% to 7% of deaths occurring in one year are not registered until the following year or later.
11 Prior to 2007, the scope for the reference year of the Death Registrations collection included:
Coverage of Causes of Death statistics
12 The ABS Causes of Death 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.
13 Deaths registered on Norfolk Island from 1 July 2016 are included in this publication. This is due to the introduction of the Norfolk Island Legislation Amendment Act 2015. Norfolk Island deaths are included in statistics for "Other Territories" as well as totals for all of Australia. Deaths registered on Norfolk Island prior to 1 July 2016 were not in scope for death statistics.
Prior to 1 July 2016, deaths of people that occurred in Australia with a usual residence of Norfolk Island were included in Australian totals, but assigned a usual residence of 'overseas'. With the inclusion of Norfolk Island as a territory of Australia in the ASGS 2016, those deaths which occurred in Australia between January and June 2016 with a usual residence of Norfolk Island were allocated to the Norfolk Island SA2 code instead of the 'overseas' category.
14 The current scope of the statistics includes:
15 The scope of the statistics excludes:
Scope of perinatal death statistics
16 The scope of the perinatal death statistics includes all registered fetal deaths (at least 20 weeks' gestation or at least 400 grams' birth weight) and all registered neonatal deaths (all live born babies who die within 28 completed days of birth, regardless of gestation or birth weight). The ABS scope rules for fetal deaths are consistent with the legislated requirement for all state and territory Registrars of Births, Deaths and Marriages to register all fetal deaths which meet the above-mentioned gestation and birth weight criteria. Based on this legislative requirement, in the case of missing gestation and/or birth weight data, the fetal record is considered in scope and included in the dataset. A record is only considered out of scope if both gestation and birth weight data are present, and both fall outside the scope criteria (i.e. gestation of 19 weeks or less and birth weight of 399 grams or fewer). This scope was adopted for the 2007 Perinatal Deaths collection, and was applied to historical data for 1999-2006. For more information on the changes in scope rules see Perinatal Deaths, Australia, 2007 (cat. no. 3304.0) Explanatory Notes 18-20. These rules have been applied to all perinatal data presented in this publication.
17 The World Health Organization (WHO) definition of a perinatal death differs to that used by the ABS. The WHO definition includes all neonatal deaths, and those fetuses weighing at least 500 grams or having a gestational age of at least 22 weeks, or body length of 25 centimetres from crown to heel. A summary table based on the WHO definition of perinatal deaths is included in the perinatal data cube in this release. See Explanatory Note 81, below, for more details on the interpretation of this table for 2017.
18 Fetal deaths are registered only as a stillbirth, and are not in scope of either the Births, Australia (cat. no. 3301.0) or Deaths, Australia (cat. no. 3302.0) collections. Fetal deaths are part of the Perinatal collection, but not the Causes of Death collection. Neonatal deaths are in scope of the Deaths, Causes of Death and Perinatal collections.
19 This publication only includes information on registered fetal and neonatal deaths. This scope differs from other Australian data sources on perinatal deaths including the National Perinatal Mortality Collection, which sources data via state and territory Perinatal Committees directly through hospital and health centres. For this reason these datasets are not directly comparable and caution should be taken when using both sources for analysis.
20 A range of socio-demographic data are available from the ABS Causes of Death collection. Standard classifications used in the presentation of causes of death statistics include age, sex, and Aboriginal and Torres Strait Islander status. Statistical standards for social and demographic variables have been developed by the ABS. Where these are not released in the Causes of Death published outputs, they can be sourced on request from the ABS.
21 Since the publication of Causes of Death, Australia, 2011, the ABS has released data based on the Australian Statistical Geography Standard (ASGS). The ASGS is a hierarchical classification system that defines more stable, consistent and meaningful areas than those of the Australian Standard Geographical Classification (ASGC), which was used to define geographical areas for output prior to the release of 2011 reference year data. Under the ASGS, causes of death statistics are coded to Statistical Area 2 (SA2) level, and are presented at the state/territory and national level in this publication.
22 The Standard Australian Classification of Countries (SACC) groups neighbouring countries into progressively broader geographic areas on the basis of their similarity in terms of social, cultural, economic and political characteristics. ABS causes of death statistics are coded using the SACC, as the collection includes overseas residents whose death occurred while they were in Australia.
23 For further information, refer to the Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2016 (cat. no. 1270.0.55.001) and the Standard Australian Classification of Countries (SACC), 2011 (cat. no. 1269.0).
International Classification of Diseases (ICD)
24 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 the ICD 10th revision is used for Australian causes of death statistics.
25 The 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:
26 For example, a systemic disease such as sepsis is grouped with infectious diseases; a disease primarily affecting one body system, such as a myocardial infarction, is grouped with circulatory diseases; and a congenital condition, such as spina bifida, is grouped with congenital conditions.
27 For further information about the ICD refer to WHO International Classification of Diseases (ICD).
28 The various versions of the ICD 10th Revision are available online.
Updates to ICD-10
29 The Update 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 the addition and deletion of codes, changes to coding instructions and modification and clarification of terms.
30 From the 2013 reference year, the ABS implemented a new automated coding system called Iris. The 2013-2017 data coded in the Iris system applied an updated version of the ICD-10 (2013 version for 2013 data, and 2015 version for 2014-2017 data) when coding multiple causes of death, and when selecting the underlying cause of death. For details of further impacts of this change from 2013 data onwards, please see the ABS Implementation of the Iris Software: Understanding Coding and Process Improvements Technical Note, in the Causes of Death, Australia, 2013 (cat. no. 3303.0) publication.
31 Prior to the 2013 reference year, the 2006 version of the ICD-10 was the most recent version used for coding deaths, with the exception of two updates that were applied after the 2006 reference year. The first update was implemented in 2007 and related to the use of mental and behavioural disorders due to psychoactive substance use, acute intoxication (F10.0, F11.0...F19.0) as an underlying cause of death. If the acute intoxication initiated the train of morbid events it is now assigned an external accidental poisoning code (X40-X49) corresponding to the type of drug used. For example, if the death had been due to alcohol intoxication, the underlying cause before the update was F10.0, and after the update the underlying cause is X45, with poisoning code T51.9. The second update implemented from the 2009 reference year was the addition of Influenza due to certain identified virus (J09) to the Influenza and Pneumonia block. This addition was implemented to capture deaths due to Swine flu and Avian flu, which were reaching health epidemic status worldwide.
32 The cumulative list of ICD-10 updates can be found online.
2013 - 2017 mortality coding
33 From the 2013 reference year onwards, the cause of death data presented in this publication was coded using the Iris coding software. This system replaced the Mortality Medical Data System (MMDS), which was used for coding cause of death data for the 1997-2012 reference years. Like MMDS, Iris is an automated coding system. Iris assigns ICD-10 codes to the diseases and conditions listed on the death certificate and then applies decision tables to select the underlying cause of death. For further details on the change to Iris coding software and associated impacts on data, please see the ABS Implementation of the Iris Software: Understanding Coding and Process Improvements Technical Note, in the Causes of Death, Australia, 2013 (cat. no. 3303.0) publication.
Types of death
34 All causes of death can be grouped to describe the type of death, whether it be from a disease or condition, or from an injury, or whether the cause is unknown. These are generally described as:
External Causes of Death
35 Where an accidental or violent death occurs, the underlying cause is classified according to the circumstances of the fatal injury, rather than the nature of the injury, which is coded separately. For example, a motorcyclist may crash into a tree (V27.4) and sustain multiple fractures to the skull and facial bones (S02.7), which leads to death. The underlying cause of death is the crash itself (V27.4), as it is the circumstance which led to the injuries that ultimately caused the death.
Leading Causes of Death
36 Ranking causes of death is a useful method of describing patterns of mortality in a population and allows comparison over time and between populations. However, different methods of grouping causes of death can result in a vastly different list of leading causes for any given population. A ranking of leading causes of death based on broad cause groupings such as 'cancers' or 'heart disease' does not identify the leading causes within these groups, which is needed to inform policy on interventions and health advocacy. Similarly, a ranking based on very narrow cause groupings or including diseases that have a low frequency, can be meaningless in informing policy.
37 Tabulations of leading causes presented in this publication are based on research presented in the Bulletin of the World Health Organization, Volume 84, Number 4, April 2006, 297-304. The determination of groupings in this list is primarily driven by data from individual countries representing different regions of the world. Other groupings are based on prevention strategies, or to maintain homogeneity within the groups of cause categories. Since the aforementioned bulletin was published, a decision was made by WHO to include deaths associated with the H1N1 influenza strain (commonly known as swine flu) in the ICD-10 classification as Influenza due to certain identified influenza virus (J09). This code has been included with the Influenza and Pneumonia leading cause grouping in the Causes of Death publication since the 2009 reference year.
38 Since 2015, the ABS includes C26.0 (malignant neoplasm of the intestinal tract, part unspecified) in the WHO leading cause grouping for Malignant neoplasm of colon, sigmoid, rectum and anus (now C18-C21, C26.0). For further details on the reasoning behind the inclusion of C26.0 in this leading cause grouping, see Complexities in the measurement of bowel cancer in Australia, in Causes of Death, Australia, 2015 (cat. no. 3303.0). This change has been applied in this publication to data for all reference years that appear in tables involving leading cause tabulations. This differs to publications prior to 2015, for which C26.0 was not included in this leading cause grouping, and also differs to the suggested WHO tabulation of leading causes for these cancers. Comparisons with data for this leading cause, and associated leading cause rankings, as they appear in previous publications should therefore be made with caution. Time-series data by leading causes has been published in Australia's leading causes of death, 2017 in this publication.
39 The ABS now includes Y87.0 (Sequelae of intentional self-harm), Y87.1 (Sequelae of assault) and Y85 (Sequelae transport accidents) in the WHO leading cause grouping for Intentional self-harm (now X60-X84, Y87.0), Assault (now X85-Y09, Y87.1) and Land transport Accidents (V01-V89, Y85). This change has been applied to harmonise data between the WHO leading cause grouping and subject specific datacubes for intentional self-harm, assault and transport accidents which is published as part of the ABS Causes of Death collection. This change applies to publication data for all reference years that appear in tables involving leading cause tabulations. This differs to previous publications, where Y87.0, Y87.1 and Y85 were not included in these leading cause groupings, and also differs to the suggested WHO tabulation of leading causes. Comparisons with data for these leading causes, and associated leading cause rankings, as they appear in previous publications should therefore be made with caution. Time-series data by leading causes has been published in Australia's leading causes of death, 2017 in this publication.
Years of Potential Life Lost (YPLL)
40 Years of Potential Life Lost (YPLL) measures the extent of 'premature' mortality, which is assumed to be any death between the ages of 1-78 years inclusive, and aids in assessing the significance of specific diseases or trauma as a cause of premature death.
41 Estimates of YPLL are calculated for deaths of persons aged 1-78 years based on the assumption that deaths occurring at these ages are untimely. The inclusion of deaths under one year would bias the YPLL calculation because of the relatively high mortality rate for that age, and 79 years was the median age at death when this series of YPLL was calculated using 2001 as the standard year. As shown below, the calculation uses the current ABS standard population of all persons in the Australian population at 30 June 2001.
42 YPLL is derived from: where: = adjusted age at death. As age at death is only available in completed years the midpoint of the reported age is chosen (e.g. age at death 34 years was adjusted to 34.5). = registered number of deaths at age due to a particular cause of death. YPLL is directly standardised for age using the following formula: where the age correction factor is defined for age as: where: = estimated number of persons resident in Australia aged 1-78 years at 30 June 2015 = estimated number of persons resident in Australia aged years at 30 June 2015 = estimated number of persons resident in Australia aged years at 30 June 2001 (standard population) = estimated number of persons resident in Australia aged 1-78 years at 30 June 2001 (standard population).
43 The data cubes contain directly standardised death rates and YPLL for males, females and persons. In some cases the summation of the results for males and females will not equate to persons. The reason for this is that different standardisation factors are applied separately for males, females and persons.
Standardised Death Rates
44 Age-standardised death rates enable the comparison of death rates over time and between populations of different age-structures. Along with adult, infant and child mortality rates, they are used to determine whether the mortality rate of the Aboriginal and Torres Strait Islander population is declining over time, and whether the gap between Aboriginal and Torres Strait Islander and non-Indigenous populations is narrowing. However, there have been inconsistencies in the way different government agencies have calculated age-standardised death rates in the past. The ABS uses the direct method of age-standardisation as it allows for valid comparisons of mortality rates between different study populations and across time. This method was agreed to by the ABS, Australian Institute of Health and Welfare (AIHW) and other stakeholders. For further information see: AIHW (2011) Principles on the use of direct age-standardisation in administrative data collections: for measuring the gap between Indigenous and non-Indigenous Australians. Cat. no. CSI 12. Canberra: AIHW.
45 The direct method has been used throughout the publication and data cubes for age-standardised death rates. Age-standardised death rates for specific causes of death with fewer than a total of 20 deaths are not available for publication, due to issues of robustness.
46 For further information, see Appendix: Principles on the use of direct age-standardisation, from Deaths, Australia, 2010 (cat. no. 3302.0).
47 In this publication, age-standardised and age-specific death rates for Aboriginal and Torres Strait Islander persons for the 2017 reference year have been calculated using 2011 Census-based population estimates, including 2013-2017 years combined. Non-Indigenous estimates have been derived by subtracting the 2011 Census based Aboriginal and Torres Strait Island population estimate from the total 2011 Census-based estimated resident population (ERP). This differs from Causes of Death 2016 (3303.0) where single-year rates calculated for the 2016 reference year, were calculated using 2016 Census-based Aboriginal and Torres Strait Islander population projections. The non-Indigenous population component were derived by subtracting the 2016 Census-based Aboriginal and Torres Strait Islander population projections from the total 2016 Census-based ERP. Rates calculated for previous reference years, including for 2012-2016 reference years combined, were calculated using 2011 Census-based Aboriginal and Torres Strait Islander population projections. The non-Indigenous population component were derived by subtracting the 2011 Census-based Aboriginal and Torres Strait Islander population projections from the total 2011 Census-based ERP. Rates calculated from population denominators derived from different Censuses may cause artificially large rate differences. Rate comparisons made between the 2017 reference year and 2016 should therefore be made with extreme caution. Aboriginal and Torres Strait Islander population estimates and projections based on the 2016 Census will be released in Estimates and Projections, Aboriginal and Torres Strait Islander Australians (cat. no. 3238.0) in 2019.
State and Territory Data
48 Causes of death statistics for states and territories in this publication have been compiled based on the state or territory of usual residence of the deceased, regardless of where in Australia the death occurred and was registered. Deaths of persons usually resident overseas which occur in Australia are included in the state/territory in which their death was registered.
49 Statistics compiled on a state or territory of registration basis are available on request.
Perinatal State and Territory Data
50 Given the small number of perinatal deaths which occur in some states and territories, some data provided on a state/territory basis in this publication have been aggregated for South Australia, Western Australia, Northern Territory, Australian Capital Territory and Other Territories.
51 In compiling causes of death statistics, the ABS employs a variety of measures to improve quality, which include:
52 The quality of causes of death coding can be affected by changes in the way information is reported by certifiers, by lags in completion of coroner cases and the processing of the findings. While changes in reporting and lags in coronial processes can affect coding of all causes of death, those coded to Chapter XVIII: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified and Chapter XX: External causes of morbidity and mortality are more likely to be affected because the code assigned within the chapter may vary depending on the coroner's findings (in accordance with ICD-10 coding rules).
53 It is the role of the coroner to investigate the circumstances surrounding all reportable deaths and to establish, wherever possible, the circumstances surrounding the death, and the cause(s) of death. Generally most deaths due to external causes will be referred to a coroner for investigation; this includes those deaths which are possible instances of intentional self-harm (suicide).
54 Where a case remains open on the NCIS at the time the ABS ceases processing, and insufficient information is 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 are assigned, as required by the ICD coding rules.
55 The specificity with which open cases are able to be coded is directly related to the amount and type of information available on the NCIS. The amount of information available for open cases varies considerably from no information to detailed police, autopsy and toxicology reports. There may also be interim findings of 'intent'.
56 The manner or intent of an injury which leads to death, is determined by whether the injury was inflicted purposefully or not. When it was inflicted purposefully (intentional), a determination should be made as to whether the injury was self-inflicted (suicide) or inflicted by another person (assault). However, intent cannot be determined in all cases.
Revisions process and other quality improvements
57 These published outputs include 2017 and 2016 preliminary data, 2015 revised data and 2014 final data. The standard ABS revisions process has not yet been applied to the 2015 and 2016 reference years that would, in the past, be subject to revisions in this publication. Causes of death revisions data (will be released in early 2019).
58 For coroner-certified deaths, the specificity of cause of death coding can be affected by the length of time for the coronial process to be finalised and the coroner case closed. To improve the quality of ICD coding, all coroner-certified deaths registered after 1 January 2006 are subject to a revisions process.
59 Up to and including deaths registered in 2005, ABS Causes of Death processing was finalised at a point in time. At this point, not all coroners' cases had been investigated, the case closed and relevant information loaded into the National Coronial Information System (NCIS). The coronial process can take several years if an inquest is being held or complex investigations are being undertaken. In these instances, the cases remain open on the NCIS and relevant reports may be unavailable. Coroners' cases that have not been closed or had all information made available can impact on data quality as less specific ICD codes often need to be applied.
60 The revisions process to date has focused on cases that remain open on the NCIS database. ABS coders investigate and use additional information from police reports, toxicology reports, autopsy reports and coroners' findings to assign more specific causes of death. The use of this additional information occurs at either 12 or 24 months after initial processing and the specificity of the assigned ICD-10 codes increase over time. As 12 or 24 months pass after initial processing, many coronial cases are closed, with the coroner having dispensed a cause of death and relevant reports become available. This allows ABS coders to assign a more specific cause of death.
65 In addition to those deaths where the deceased is identified as an Aboriginal and Torres Strait Islander person, a number of deaths occur each year for which the Indigenous status is not stated on the death registration form. In 2017, there were 966 deaths registered in Australia for whom Indigenous status was not stated, representing 0.6% of all deaths registered, remaining consistent with 0.6% in 2016, yet representing an increase from 2015 (0.3%). This difference is largely driven by a higher number of deaths with a not stated Indigenous status registered in New South Wales (from 343 in 2016 to 599 in 2017), and Victoria (from 120 in 2016 to 144 in 2017). Queensland deaths where indigenous status was not stated decreased from 240 in 2016 to 53 in 2017. See Explanatory Note 61-64 for further details.
66 Data presented in this publication may therefore underestimate the level of Aboriginal and Torres Strait Islander deaths and mortality in Australia. Caution should be exercised when interpreting data for Aboriginal and Torres Strait Islander Australians presented in this publication, especially with regard to year-to-year changes.
67 Information on causes of death relating to Aboriginal and Torres Strait Islander persons is included in articles throughout this publication. Data cube 12 also provides information on causes of death for Aboriginal and Torres Strait Islander Australians. In this data cube 12, numbers and rates of death are reported by jurisdiction of usual residence for New South Wales, Queensland, South Australia, Western Australia and the Northern Territory only. Data for Victoria, Tasmania and the Australian Capital Territory have been excluded in line with national reporting guidelines. For information on issues with Aboriginal and Torres Strait Islander identification, see Explanatory Notes 61-73.
68 Individual state/territory disaggregations of deaths of Aboriginal and Torres Strait Islander Australians by WHO Leading Causes (see Explanatory Notes 36-39) for the 2017 reference year are presented for New South Wales, Queensland, Western Australia and the Northern Territory only. No data are presented for South Australia, due to the small number of deaths by WHO leading causes - most causes have a count of fewer than 20 deaths, which is too small for the production of robust Standardised Death Rates (SDRs). See Explanatory Notes 44-47 for further details.
69 In this publication, age-standardised and age-specific death rates for Aboriginal and Torres Strait Islander persons for the 2017 reference year have been calculated using 2011 Census-based population estimates, including 2013-2017 years combined. Non-Indigenous estimates have been derived by subtracting the 2011 Census based Aboriginal and Torres Strait Island population estimate from the total 2011 Census-based estimated resident population (ERP). This differs from Causes of Death 2016 (3303.0) where single-year rates calculated for the 2016 reference year, were calculated using 2016 Census-based Aboriginal and Torres Strait Islander population projections. The non-Indigenous population component were derived by subtracting the 2016 Census-based Aboriginal and Torres Strait Islander population projections from the total 2016 Census-based ERP. Rates calculated for previous reference years, including for 2012-2016 reference years combined, were calculated using 2011 Census-based Aboriginal and Torres Strait Islander population projections. The non-Indigenous population component were derived by subtracting the 2011 Census-based Aboriginal and Torres Strait Islander population projections from the total 2011 Census-based ERP. Rates calculated from population denominators derived from different Censuses may cause artificially large rate differences. Rate comparisons made between the 2017 reference year and 2016 should therefore be made with extreme caution. Aboriginal and Torres Strait Islander population estimates and projections based on the 2016 Census will be released in Estimates and Projections, Aboriginal and Torres Strait Islander Australians (cat. no. 3238.0) in 2019.
70 Coronial cases are more likely to be affected by a lag in registration time, especially those which are due to external causes, including suicide, homicide and drug-related deaths. Due to small numbers these lagged coroner-referred registrations can create large yearly variation in some causes of deaths of Aboriginal and Torres Strait Islander persons. Caution should be taken when making year to year analysis.
71 The ABS undertakes significant work aimed at improving Aboriginal and Torres Strait Islander identification. The ABS is working closely with the state and territory registries of births, deaths and marriages through the National Civil Registration and Statistics Improvement Committee (NCRSIC) to progress towards improved identification in a nationally consistent way.
72 Quality studies conducted as part of the Census Data Enhancement (CDE) project have investigated the levels and consistency of Aboriginal and Torres Strait Islander identification between the 2011 Census and death registrations. See Information Paper: Death registrations to Census linkage project - Methodology and Quality Assessment, 2011-2012 (cat. no. 3302.0.55.004).
73 An assessment of various methods for adjusting incomplete Aboriginal and Torres Strait Islander death registration data for use in compiling Aboriginal and Torres Strait Islander life tables and life expectancy estimates is presented in Discussion Paper: Assessment of Methods for Developing Life Tables for Aboriginal and Torres Strait Islander Australians, 2006 (cat. no. 3302.0.55.002), released on 17 November 2008. Final tables based on feedback received from this discussion paper, using information from the Census Data Enhancement (CDE) study, can be found in Life Tables for Aboriginal and Torres Strait Islander Australians, 2010-2012 (cat. no. 3302.0.55.003).
Deaths by type of certifier
74 For deaths in the 2017 reference year, 11.9% were certified by a coroner. There are variations between jurisdictions in relation to the proportion of deaths certified by a coroner, ranging from 8.7% of deaths certified by a coroner and registered in Queensland, to 29% of deaths certified by a coroner and registered in the Northern Territory. The proportion of deaths certified by a coroner in 2016 is comparable to previous years.
Issues to be considered when interpreting time-series and 2017 data
75 The 2017 publication has followed the same process of publication as the 2016 data. The 2016 publication was released six months earlier than usual, allowing for more timely access to mortality data in Australia. For further details on data considerations, see A more timely annual collection: changes to ABS processes (Technical Note), Causes of Death, Australia, 2015 (cat. no. 3303.0).
Use of Iris as a new auto-coding system and implementation of updates to ICD-10
76 From the 2013 reference year onwards, the cause of death data presented in this publication was coded using the Iris coding software. This system replaced the Mortality Medical Data System (MMDS), which was used for coding cause of death data for the 1997-2012 reference years. Like MMDS, Iris is an automated coding system. Iris assigns ICD-10 codes to the diseases and conditions listed on the death certificate and then applies decision tables to select the underlying cause of death. For further details on the change to Iris coding software and associated impacts on data, please see the ABS Implementation of the Iris Software: Understanding Coding and Process Improvements Technical Note, in the Causes of Death, Australia, 2013 (cat. no. 3303.0) publication.
77 Users analysing time-series or 2017 cause of death data should take into account a number of issues, as outlined below, which are unrelated to the implementation of Iris.
Coding of perinatal deaths
78 For perinatal data output in the Causes of Death, Australia, 2013 publication, the ABS began a review of its method of coding perinatal deaths, which resulted in an interim change to how this data was output. One significant change was that neonatal deaths were not assigned an underlying cause of death when output in tables of all ages, as had previously occurred. (Details of this change can be found in the Changes to Perinatal Death Coding Technical Note in Causes of Death, Australia, 2013 (cat. no. 3303.0). Further review and consultation has now been undertaken with the national and international coding community, and has resulted in the ABS applying a new method of coding perinatal deaths. The new method creates a sequence of causes on a Medical Certificate of Cause of Perinatal Death which allows for an underlying cause of death to be assigned to a neonatal death. This aligns the output for neonatal deaths to deaths of the general population which are certified using the Medical Certificate of Cause of Death. The change in coding method reinstates the condition arising in the mother being assigned as an underlying cause of death. This method has been applied to the 2014-2017 data, and has also been applied retrospectively to the 2013 neonatal data that is output in tables of all ages in this publication, thus enabling a consistent time-series. Please see the Changes to Perinatal Death Coding Technical Note in Causes of Death, Australia, 2014 (cat. no. 3303.0) for further details.
79 From the 2013 reference year onwards, process changes have led to a reduction in the number of both stillbirths and neonatal deaths where a 'main condition in mother' was recorded, compared to previous years. This has led to a reduction in the number of records assigned within the code block P00-P04: Fetus and newborn affected by maternal factors and by complications of pregnancy, labour and delivery, as main condition in the mother. These changes will affect data output in the Perinatal data cube of this publication only.
80 Doctor-certified neonatal deaths with no cause of death information are coded to Conditions originating in the perinatal period, unspecified (P969). As these deaths have been certified by a doctor, the assumption is made that the neonate died of natural causes. Where a neonatal death is referred to a coroner, but no cause of death information is available, these deaths are coded to Other ill-defined and unspecified causes of mortality (R99). As a reportable death, it cannot be determined whether the neonate died of natural or external causes, in the absence of further information.
81 The count of fetal deaths in scope for the World Health Organization (WHO) definition of perinatal deaths differs to those previously published for 2012 and 2015. This is due to an enhancement to birth weight and gestation information, which resulted in some deaths no longer meeting the World Health Organization definition of a fetal death (that is, a gestational age of at least 22 weeks or weighing at least 500 grams). For 2012, there are two fewer fetal deaths than previously published (1 male and 1 female). For 2015, there are 38 fewer fetal deaths than previously published (18 males, 19 females, 1 death of undetermined sex). Some corresponding death rates have also been affected. Table 14.21 in the perinatal data cube presents fetal and neonatal data according to the WHO scope. No other tables in the perinatal deaths data cube are affected by these changes.
Increased number of deaths, New South Wales
82 In September quarter 2011 the high number of death registrations in New South Wales was queried with the New South Wales Registry of Births, Deaths and Marriages. Information provided by the Registry indicates that these fluctuations may be the result of changes in processing rates. This may have contributed to the increase in the number of deaths registered in New South Wales in 2011. New South Wales deaths in 2011 (50,182) were 5.8% higher than in 2010 (47,453).
Accident to watercraft causing drowning and submersion (V90)
83 The number of deaths attributable to Accident to watercraft causing drowning and submersion (V90) increased from 26 in 2010 to 75 in 2011. This increase is primarily due to deaths resulting from an incident in December 2010 when a boat collided with cliffs on Christmas Island. These deaths were registered with the Western Australian Registry of Births, Deaths and Marriages in January 2011, resulting in an increase in the number of deaths coded to V90 in Western Australia.
Intentional Self-Harm (Suicide) (X60-X84, Y87.0)
91 The number of deaths attributed to intentional self-harm for 2017 is expected to increase as data is subject to the revisions process. For further information, see Explanatory Notes 57-60 and A more timely annual collection: changes to ABS processes (Technical Note) in Causes of Death, Australia, 2015 (cat. no. 3303.0). See also the Causes of Death Revisions, 2014 Final Data (Technical Note) in Causes of Death, Australia, 2016 for further details.
92 From 2006 onwards, the ABS implemented a revisions process for coroner-certified deaths (such as suicides), which has enabled additional suicide deaths to be identified beyond initial processing (see Explanatory Notes 52-60). It is recognised that in the four years prior to the implementation of the revisions process (2002-2005), suicide deaths may have been understated as the ABS began using the National Coronial Information System as the sole source for coding coroner-referred deaths.
93 In addition to the revisions process, new coding guidelines were applied for deaths registered from 1 January 2007. The new guidelines improve data quality by enabling deaths to be coded to suicide if evidence indicates the death was from intentional self-harm. Previously, coding rules required a coroner to determine a death as intentional self-harm for it to be coded to suicide. However, in some instances the coroner does not make a finding on intent. The reasons for this may include legislative or regulatory barriers around the requirement to determine intent, or sensitivity to the feelings, cultural practices and religious beliefs of the family of the deceased. Further, for some mechanisms of death it may be very difficult to determine suicidal intent (e.g. single vehicle incidents, drowning). In these cases the burden of proof required for the coroner to establish that the death was as a result of intentional self-harm may make a finding of suicide less likely.
94 Under the new coding guidelines, in addition to coroner-determined suicides, deaths may also be coded to suicide following further investigation of information on the NCIS. Further investigation of a death would be initiated when the mechanism of death indicates a possible suicide and the coroner does not specifically state the intent as accidental or homicidal. Information that would support a determination of suicide includes indications by the person that they intended to take their own life, the presence of a suicide note, or knowledge of previous suicide attempts. The processes for coding open and closed coroner cases are illustrated in the below diagrams (open/closed case coding decision trees).
95 Over time, the NCIS has worked with jurisdictions to improve the timeliness and completeness of information flowing from the coronial systems to the NCIS database. These improvements lead to changes in the information available to ABS coding staff. It is therefore important that data users are aware of any significant improvements in the management of coronial data to enable better interpretation of data within, and between, reference periods.
Registration of Outstanding Deaths, Queensland
101 In November 2010, the Queensland Registrar of Births, Deaths and Marriages advised the ABS of an outstanding deaths registration initiative undertaken by the registry. This initiative resulted in the November 2010 registration of 374 previously unregistered deaths which occurred between 1992 and 2006 (including a few for which a date of death was unknown). Of these, around three-quarters (284) were deaths of Aboriginal and Torres Strait Islander Australians. A data adjustment is made for tables which include Aboriginal and Torres Strait Islander data for Queensland for 2010. For further information refer to Technical Notes, Registration of Outstanding Deaths, Queensland, 2010 in Deaths, Australia, 2010 (cat. no. 3302.0) and Retrospective Deaths by Causes of Death, Queensland, 2010, in Causes of Death, Australia, 2010 (cat. no. 3303.0).
102 See the 'Data Used in Calculating Death Rates' Appendix for details of the number of live births registered which have been used to calculate the fetal, neonatal and perinatal death rates shown in this publication. This Appendix also provides data on fetal deaths used in the calculation of fetal and perinatal death rates. These also enable further rates to be calculated.
Use of Multiple Cause of Death data
104 Multiple causes of death include all causes and conditions reported on the death certificate (i.e. both underlying and associated causes; see the Glossary for further details). As all entries on the death certificate are taken into account, multiple cause of death statistics are valuable in recognising the impact of conditions and diseases which are less likely to be an underlying cause, highlighting relationships between concurrent disease processes, and giving an indication of injuries which occur as a result of specific external events. These features of multiple cause of death data provide a more in depth picture of mortality in Australia.
105 When analysing data on multiple causes of death, data can be presented in two ways: by counts of deaths or by counts of mentions. When analysis is conducted by counts of death, the figures are describing the number of people who have died with a particular disease or disorder. Multiple Cause of Death data derived from counts of mentions is the total number of incidences of a particular disease or disorder on the death certificate. For example, an individual may have had Breast cancer (C50) and then developed Secondary lung cancer (C78.0). This individual would be counted once if counts were by the number of deaths from cancer, but twice if the counts were by the number of mentions of cancer. Care should be taken to differentiate between counts and mentions when analysing multiple cause of death data.
106 Changes in patterns of mortality are studied by policy makers and researchers to improve health outcomes for all Australians. However, changes in patterns of mortality can occur for many reasons. Changes can reflect a real increase or decrease in the prevalence of a disease or disorder, or a change in medical treatment. Mortality data changes can also be a result of administrative processes which can potentially impact on the data, for example, International Classification of Disease (ICD) coding classification changes and updates, and differences in how deaths are certified. Analysis of the multiple causes of death data can give a deeper understanding of how the complete dataset may be affected by both real and administrative changes. For example, in 2009, the World Health Organization (WHO) recommended introducing code J09 (Influenza due to certain identified influenza virus) to the ICD-10 in response to the worldwide epidemics of swine flu and avian flu. There were 98 people who died as a direct consequence of contracting these strains of the flu across 2009 and 2010. In addition there were 51 people who had this flu when they died and for whom this would have been a complicating factor. Additional health risk factors may also be identified. When swine or avian flu was the underlying cause of death, multiple cause data shows obesity and respiratory problems as a common associated cause. In this way, multiple cause data provides policy makers and researchers a greater insight beyond the underlying cause of death.
Confidentialisation of data
107 Data cells with small values have been randomly assigned to protect confidentiality. As a result some totals will not equal the sum of their components. Cells with 0 values have not been affected by confidentialisation.
Effects of rounding
108 Where figures have been rounded, discrepancies may occur between totals and sums of the component items.
109 ABS published outputs are available free of charge from the ABS website. 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.
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