National Perinatal Data Collection, 2018: Quality Statement

Identifying and definitional attributes

• AIHW Data Quality Statements, Superseded 28/06/2021

Data quality

The National Perinatal Data Collection (NPDC) is a national population-based cross-sectional collection of data on pregnancy and childbirth. The data are based on births reported to the perinatal data collection in each state and territory in Australia. Midwives and other birth attendants, using information obtained from mothers and from hospital or other records, complete notification forms for each birth. A standard de-identified extract is provided to the Australian Institute of Health and Welfare (AIHW) on an annual basis to form the NPDC.

Information is included in the NPDC for both live births and stillbirths, where gestational age is at least 20 weeks or birthweight is at least 400 grams, except in Victoria and Western Australia, where births are included if gestational age is at least 20 weeks or, if gestation is unknown, birthweight is at least 400 grams.

The Australian Institute of Health and Welfare (AIHW) is a major national agency set up by the Australian Government under the Australian Institute of Health and Welfare Act 1987 to provide reliable, regular and relevant information and statistics on Australia's health and welfare. It is an independent Commonwealth entity established in 1987, governed by a management Board, and accountable to the Australian Parliament through the Health Portfolio.

The AIHW aims to improve the health and wellbeing of Australians through better health and welfare information and statistics. It collects and reports information on a wide range of topics and issues, ranging from health and welfare expenditure, hospitals, disease and injury, and mental health, to ageing, homelessness, disability and child protection.

The Institute also plays a role in developing and maintaining national metadata standards. This work contributes to improving the quality and consistency of national health and welfare statistics. The Institute works closely with governments and non-government organisations to achieve greater adherence to these standards in administrative data collections to promote national consistency and comparability of data and reporting.

One of the main functions of the AIHW is to work with the states and territories to improve the quality of administrative data and, where possible, to compile national datasets based on data from each jurisdiction, to analyse these datasets and disseminate information and statistics.

The Australian Institute of Health and Welfare Act 1987, in conjunction with compliance to the Privacy Act 1988, ensures that the data collections managed by the AIHW are kept securely and under the strictest conditions with respect to privacy and confidentiality.

For further information see the AIHW website www.aihw.gov.au.

Data for the NPDC were supplied to the AIHW by state and territory health authorities under the terms of the National Health Information Agreement.

The state and territory health authorities receive these data from patient administrative and clinical records, with the information usually collected by midwives or other birth attendants. States and territories use these data for service planning, monitoring and internal and public reporting.

Data specifications for the NPDC are documented in the AIHW’s online metadata repository, METeOR, and the Maternity Information Matrix:

METeOR—AIHW online metadata repository:

• Perinatal NMDS 2014-18
• Perinatal NMDS 2018-19

Maternity Information Matrix

NPDC data are collated annually for calendar years. Most jurisdictions need at least 12 months lead time to undertake data entry, validation and linking with hospitals data as required after the end of the data collection period. Data for 2018 were requested to be submitted to the AIHW in a staggered approach between 26 July 2019 and 6 December 2019. Seven of 8 jurisdictions provided at least one data submission within this timeframe. Final and useable data were received from all jurisdictions by 27 March 2020. Data are published annually in Australia’s mothers and babies, with 2018 data published on 26 May 2020, 17 months after the end of the data collection period.

A variety of products draw upon the NPDC. Products published by the AIHW that are based primarily on data from the NPDC include:

• Australia’s mothers and babies in brief report
• Australia's mothers and babies data visualisations
• National Core Maternity Indicators reports and data visualisations. 

Australia’s mothers and babies 2018—in brief is the twenty-eighth annual report on pregnancy and childbirth in Australia, providing national information on women who gave birth in 2018 and the characteristics and outcomes of their babies.

Ad hoc data are also available on request (charges apply to recover costs).

Data for selected indicators are also included in AIHW and other products such as:

AIHW products

• Australia’s health 2018
• Australia's health performance framework
• Children's Headline Indicators
• Aboriginal and Torres Strait Islander health performance framework.

Other products

• National Healthcare Agreement performance information
• National Indigenous Reform Agreement performance information
• National Partnership Agreement on Indigenous Early Childhood Development
• Overcoming Indigenous disadvantage
• Report on Government Services.

Supporting information on the quality and use of the NPDC is published annually in Australia’s mothers and babies—in brief(Appendix A and D in the 2018 edition).

Metadata information for the NPDC are published in the National Health Data Dictionary (NHDD) on METeOR and in the Maternity Information Matrix. Comprehensive information on the quality of Perinatal NMDS elements is published in the report Perinatal National Minimum Data Set compliance evaluation: 2010–2015.

Readers are advised to read caveat information to ensure appropriate interpretation of data.

The NPDC comprises data items as specified in the Perinatal National Minimum Data Set (NMDS), plus additional items collected by the states and territories. The purpose of the NPDC is to collect information about births for monitoring pregnancy, childbirth and the neonatal period for both the mother and baby.

The NPDC is a specification for data collected on all births in Australia in hospitals, birth centres and the community. It includes information for both live births and stillbirths, where gestational age is at least 20 weeks or birthweight is at least 400 grams. Live births and stillbirths may include termination of pregnancy after 20 weeks. Stillbirths can include fetus papyraceous and fetus compressus. In Victoria and Western Australia, data were included for both live births and stillbirths of at least 20 weeks' gestation or, if gestation was unknown, the birthweight was at least 400 grams. In South Australia, data may not include all terminations of pregnancy for psychosocial reasons after 20 weeks gestation where birthweight was not recorded.

The NPDC includes data items relating to the mother—including demographic characteristics and factors relating to the pregnancy, labour and birth—and data items relating to the baby—including birth status (live birth or stillbirth), sex, gestational age at birth, birthweight and neonatal morbidity and deaths.

A program of national perinatal data development has led to improvements in data provision and reporting. The program involves revision of existing Perinatal NMDS and National Best Endeavours Data Set (NBEDS) data elements, data development work on existing perinatal METeOR data elements and the development of new perinatal data elements. Developments to the Perinatal NMDS and NBEDS are underway to include additional data elements, such as alcohol use in pregnancy, mental health screening and family violence screening. Due to the time lag between development, implementation and collection of data by the state and territory perinatal data collections and their inclusion in the NPDC, these items will not appear in published data until after 2022, subject to quality assessment. New data elements introduced into the NPDC in the reference period may not be available for the entire period.

Inaccurate responses may occur in all data provided to the AIHW. The AIHW does not have direct access to state and territory perinatal records to determine the accuracy of the data provided. However, the AIHW does undertake validation on all data provided by the states and territories. Data received from the states and territories are checked for completeness, validity and logic errors. Potential errors are queried with jurisdictions, and corrections and resubmissions are made in response to these edit queries.

Errors may occur during the processing of data by the states and territories or at the AIHW. Processing errors before data supply may be found through the validation checks applied by the AIHW. The AIHW does not adjust data to account for possible data errors or to correct for missing data.

Before publication, data are referred back to jurisdictions for checking and review. Note that because of data editing and subsequent updates of state and territory databases, numbers reported may differ from those in reports published by the states and territories.

According to the NHDD, Indigenous status is a measure of whether a person identifies as being of Aboriginal and Torres Strait Islander origin. All states and territories have a data item to record Indigenous status of the mother and Indigenous status of the baby on their perinatal form, although there are some differences among the jurisdictions.

Neonatal deaths collected as part of the NPDC may be incomplete. In some jurisdictions, neonatal deaths for babies transferred to another hospital or readmitted to hospital, and those dying at home, may not be included. Neonatal deaths for the Northern Territory are considered to be incomplete for 2018 as data do not include deaths occurring outside the Northern Territory. Differences in mortality rates may be due to the small number of deaths, which result in statistical fluctuations, under-ascertainment, or actual differences in mortality experience.

Freebirths may be included in the NPDC if they are in scope of the data collection, and the mother or baby present to hospital following birth or the birth is registered with the Registry of Births, Deaths and Marriages. However, this differs by state and territory.

NPDC data are reported and published annually by the AIHW. While definitions and data domains of some data elements have changed over time as a result of data development, in most cases it is possible to map these changes and make consistent comparisons over time.

The other national data sources on perinatal data are the Australian Bureau of Statistics (ABS) and the AIHW’s National Hospital Morbidity Database (NHMD). The ABS compiles statistics and publishes reports on registrations of live births and perinatal deaths from data made available by the Registrars of Births, Deaths and Marriages in each state and territory. The ABS collection includes all live births that were not previously registered and stillbirths of at least 400 grams, or of at least 20 weeks gestation where birthweight is unknown. The AIHW NHMD is compiled from data supplied by the state and territory health authorities. It is a collection of electronic confidentialised summary records for separations (that is, episodes of admitted patient care) in public and private hospitals in Australia, and includes information on all births in hospital, and some that occur while the mother is on the way to a hospital.

As these collections differ from the NPDC in scope, collection methodology, definitions and reference periods, comparisons between collections should be made with caution.

Data products

Source and reference attributes

 Australian Institute of Health and Welfare

Relational attributes