Quality Declaration- Perinatal data, summary
Perinatal deaths statistics refer to all fetal (stillbirth) deaths of at least 20 weeks gestation or at least 400 grams birth weight, and neonatal deaths (all live born babies who die within 28 days of birth, regardless of gestation or weight).
For further information on the institutional environment of the ABS, including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.
Statistics on perinatal deaths presented in Causes of Death, Australia, 2018 (cat. no. 3303.0) are sourced from death registrations administered by the various state and territory Registry of Births, Deaths and Marriages. It is a legal requirement of each state and territory that all neonatal deaths and those fetal deaths of at least 20 weeks gestation or 400 grams birth weight are registered. As part of the registration process, information on the cause of death is either supplied by the medical practitioner certifying the death on a Medical Certificate of Cause of Perinatal Death, or supplied as a result of a coronial investigation.
Death records are provided electronically and/or in paper form to the Australian Bureau of Statistics (ABS) by individual Registrars on a monthly basis. Each death record contains both demographic data and medical information from the Medical Certificate of Cause of Perinatal Death, where available. Information from coronial investigations are provided to the ABS through the National Coroners Information System (NCIS).
Perinatal statistics provide valuable information for the analysis of fetal, neonatal and perinatal deaths in Australia. This publication presents data at the national and state level on registered perinatal deaths by sex, state of usual residence, main condition in fetus/infant, main condition in mother and Aboriginal and Torres Strait Islander status. Fetal, neonatal and perinatal death rates are also provided.
The ABS Causes of Death collection includes all perinatal deaths that occurred and were registered in Australia, including deaths of persons whose usual residence is overseas. Deaths registered on Norfolk Island from 1 July 2016 are also included due to the introduction of the Norfolk Island Legislation Amendment Act 2015. See Explanatory Note 13 in Causes of Deaths, Australia, 2018 (cat. no. 3303.0) for more information. Deaths of Australian residents that occurred outside Australia may be registered by individual Registrars, but are not included in ABS deaths or perinatal deaths statistics.
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. More information about the scope of the perinatal deaths statistics can be found in Explanatory Notes 16 to 20 in this publication.
Since the 2006 reference year, the scope of the perinatal death statistics has included all fetal deaths of at least 20 weeks gestation or at least 400 grams birth weight, and all neonatal deaths (all live born babies who die within 28 days of birth, regardless of gestation or weight) which are:
- all deaths registered in Australia for the reference year and 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.
For example, records received by the ABS during the March quarter of 2019 which were initially registered in 2018 or prior (but not forwarded to the ABS until 2019) are assigned to the 2018 reference year. Any death registrations relating to the 2018 reference period which are received by the ABS after the end of the March 2019 quarter are assigned to the 2019 reference year.
Data in the Perinatal deaths collection include causes of death information, as well as some demographic items. Causes of death information is obtained from the Medical Certificate of Cause of Perinatal Death (perinatal deaths) and the National Coronial Information System (coroner-certified deaths). Causes of death are coded according to the International Classification of Diseases (ICD).
Issues for perinatal deaths data:
- The primary objective of the owner of the source data can differ from the information needs of the statistical users. Registrars of Births, Deaths and Marriages and coroners have legislative and administrative obligations to meet, as well as being the source of statistics. As a result, the population covered by the source data, the time reference period for some data, and the data items available in the registration system, may not align exactly with the requirements of users of the statistics.
- There can be differences between the defined scope of the population (i.e. every death occurring in Australia) and the actual coverage achieved by the registration system. Levels of registration can be influenced by external factors and coverage achieved will be influenced by the steps taken by the owners of death registration systems to ensure all deaths are registered.
- There are eight different registration systems within Australia. Each jurisdiction's registration system, while similar in many ways, also has a number of differences. These can include the types of data items collected, the definition of those collected data items, and business processes undertaken within Registries of Births, Deaths and Marriages including coding and quality assurance practices.
Causes of Death, Australia dataset is released annually, approximately nine months after the end of the reference period and in conjunction with Deaths, Australia 2017 (cat. no. 3302.0). Perinatal deaths data are included in the Causes of Death, Australia 2018
(cat. no. 3303.0) published outputs.
Prior to the release of the 2015 dataset, Causes of Death data had been released approximately 15 months after the end of the reference period, however changes to ABS processes allowed for more timely access to Australian mortality data. For more information see A more timely annual collection: changes to ABS processes
(Technical Note) in Causes of Death, Australia, 2015 (cat. no. 3303.0).
There is a focus on fitness for purpose when causes of death statistics are released. To meet user requirements for accurate causes of death data it is necessary to obtain information from other administrative sources before all information for the reference period is available. This specifically applies to coroner certified deaths, where extra information relating to the death is provided through police, toxicology, autopsy and coronial finding reports. A balance therefore needs to be maintained between accuracy (completeness) of data and timeliness. ABS provides the data in a timely manner, ensuring that all coding possible can be undertaken with accuracy prior to publication.
As coroner certified deaths can have ill-defined causes of death until a case is closed within the coronial system, a revisions process was introduced that applies to all neonatal coroner certified deaths registered after 1 January 2006 to enhance the cause of death output for open coroner cases (causes of death for fetal deaths are not revised). This process enables the use of additional information for coding relating to coroner certified deaths at approximately 12 and/or 24 months after initial processing. See Explanatory Notes 59-62 in this publication and Causes of Death Revisions, 2015 Final Data (Technical Note) and 2016 Revised Data (Technical Note) in Causes of Death, Australia, 2017 (cat. no. 3303.0) for more information on the revisions process.
Causes of Death, Australia, 2018, includes preliminary neonatal data for 2018 and 2017, revised data for 2016 and final data for 2015 and prior years. Revised output for the 2016 and 2017 data will be released in early 2020. All data relating to fetal deaths is final.
Issues for perinatal deaths data:
- A balance is maintained between accuracy (completeness) and timeliness, taking into account the different needs of users and maximising the fitness for purpose of the data. Documentation including explanatory notes and technical notes are provided for causes of death statistics. These should be used to assess the fitness for purpose of the data to ensure informed decisions can be made.
- The timeliness of administrative information that supports cause of death coding can be impacted by legislative requirements, systems and resources available to maintain/update systems.
Non-sampling errors may influence accuracy in datasets which constitute a complete census of the population, such as the Causes of Death collection. Non-sampling error arises from inaccuracies in collecting, recording and processing the data. Every effort is made to minimise non-sampling error by working closely with data providers, undertaking quality checks throughout the data processing cycle, training of processing staff, and efficient data processing procedures.
The ABS has implemented a revisions process that applies to all coroner-
certified neonatal deaths registered after 1 January 2006. This is a change from preceding years where all ABS processing of causes of death data for a particular reference period was finalised approximately 13 months after the end of the reference period. The revisions process enables 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. See Explanatory Notes 59-62 in this publication and Causes of Death Revisions, 2015 Final Data (Technical Note) and 2016 Revised Data (Technical Note) in Causes of Death, Australia, 2017 (cat. no. 3303.0) for more information on the revisions process.
Issues for perinatal deaths data:
- Completeness of an individual record at a given point in time (e.g. incomplete causes of death information due to non-finalisation of coronial proceedings);
- Completeness of the dataset e.g. impact of registration lags, processing lags and duplicate records;
- Extent of coverage of the population (whilst all deaths are legally required to be registered some cases may not be registered for an extended time, if at all);
- Some lack of consistency in the application of questions or forms used by administrative data providers.
- Question and ‘interviewer’ biases given that information for death registrations are supplied about the person by someone else. For example, Aboriginal and Torres Strait Islander identification as reported by a third party can be different from self reported responses on a form; and
- Level of specificity and completeness in coronial reports or doctor's findings on the Medical Certificate of Cause of Perinatal Death will impact on the accuracy of coding.
- Errors in the coding of the causes of a death to ICD-10. The majority of cause of death coding is undertaken through an automated coding process, which is estimated to have a very high level of accuracy. Human coding can be subject to error, however the ABS mitigates this risk through rigorous coder training, detailed documentation and instructions for coding complex or difficult cases, and extensive data quality checks.
- Cases where coronial proceedings remain open at the end of ABS processing for a reference period are potentially assigned a less specific ICD-10 cause of death code.
- Where coroner-certified deaths become closed during the revisions process, additional information is often made available, making more specific coding possible.
Use of the explanatory notes and technical notes released with the statistics is important for assessing coherence within the dataset and when comparing the statistics with data from other sources. Changing business rules over time and/or across data sources can affect consistency and hence interpretability of statistical output, especially when assessing time series data.
The ICD is the international standard classification for epidemiological purposes and is designed to promote international comparability in the collection, processing, classification, and presentation of cause of death statistics. The classification is used to classify diseases, conditions, injuries and external events as recorded on many types of medical records as well as death records. It is used for both morbidity and mortality purposes, with the morbidity version incorporating clinical modifications. The ICD is revised periodically to incorporate changes in the medical field. The 10th revision of ICD (ICD-10) is used for the 2018 data.
Issues for perinatal deaths data:
- Changes to questions, scope etc. over time can affect the consistency of data collected over the period, even when the source of the data is the same. These changes can be the result of legislative or program objective changes.
- The completeness or quality of older versus newer data can also impact on comparisons across time or domains.
- Statistical concepts for questions are not always suited to the administrative purpose or the means of collection.
In 2014, the ABS implemented Iris, a new automated coding software product for assisting in the processing of cause of death data, and improved a number of coding practices to realign with international best practice. As part of this, the ABS began a review of its method of coding neonatal deaths which, for the 2013-2018 data published in this issue, has meant a change to the method used for assigning an underlying cause of death to neonatal deaths. It is advised that data users refer to the Changes to Perinatal Death Coding
Technical Note in Causes of Death, Australia, 2014, for further information on changes to the perinatal dataset.
The 2018 reference year cause of death data presented in this publication was coded using the 2016 version (version 5.4.0) of Iris software. This system replaced Iris version 4.4.1 which was used to code the 2013-2017 cause of death data. Version 5.4.0 of the Iris software applied the World Health Organization (WHO) ICD-10 updates and a new underlying cause of death processing system called the Multicausal and Unicausal Selection Engine (MUSE). This has resulted in changes to the automated coding path for some causes of death. The implementation of MUSE, alongside the updates to the ICD-10, align the Australian mortality data up to date with international best practice. The ABS have also implemented extra validation processes with the implementation of MUSE to ensure maximum alignment with WHO guidelines and coding rules.
It is advised that data users refer to the below technical notes for further details:
- Technical Note 1, Updates to Iris coding software: Implementing WHO updates and improvements in coding processes, in Causes of Death, Australia, 2018 (cat. no. 3303.0);
- Technical Note 1, Changes to Perinatal Death Coding, in Causes of Death, Australia, 2014 (cat. no. 3303.0); and
- Technical Note 1, ABS Implementation of the Iris Software: Understanding Coding and Process Improvements, in Causes of Death, Australia, 2013 (cat. no. 3303.0).
The Causes of Death, Australia (cat. no. 3303.0) publication contains detailed Explanatory Notes, Appendices and a Glossary in each issue that provide information on the data sources, terminology, classifications and other technical aspects associated with these statistics.
Issues for perinatal deaths data:
- Information on some aspects of statistical quality may be hard to obtain as information on the source data has not been kept over time. This is related to the issue of the administrative rather than statistical purpose of the collection of the source data.
- Changes to data processing practices, such as the implementation of new software, updates to causes of death classifications, or changes to local coding practices, should be taken into consideration when comparing data over time.
In addition to the information provided in the commentary, a series of data cubes are also available providing detailed breakdowns by cause of death. The ABS observes strict confidentiality protocols as required by the Census and Statistics Act (1905). This may restrict access to data at a very detailed level which is sought by some users.
Issues for causes of death data:
- Often an administrative source can provide the basis for statistical information which has a different nature and focus to the source's principal administrative purpose. There may be a reduced focus or availability of funding within the program to ensure the accessibility of information for non-administrative uses.
- Each jurisdiction has its own legislation governing death registration as well as that governing the coronial process. Jurisdictions also have privacy legislation which governs the accessibility of the statistics.
- The ABS observes strict confidentiality protocols as required by the Census and Statistics Act (1905). This may restrict access to data at a very detailed level which is sought by some users.
- A national causes of death unit record file which contains neonatal deaths data (but does not include fetal deaths data) can be obtained through the Australian Coordinating Registry (which is housed at the Queensland Registry of Births, Deaths and Marriages) by sending an email to BDM.CODURF@justice.qld.gov.au (data available on application for legitimate research purposes only).
If the information you require is not available from the publication or the data cubes, then 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 email@example.com
outlines how the ABS will handle any personal information that you provide to the ABS.