National Perinatal Data Collection, 2011: Quality Statement

Identifying and definitional attributes

Metadata item type:Quality Statement
METeOR identifier:587327
Registration status:AIHW Data Quality Statements, Archived 03/07/2020

Data quality

Quality statement summary:

The NPDC is a national population-based cross-sectional data collection of 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 staff, using information obtained from mothers and from hospital or other records, complete notification forms for each birth. Selected information is compiled annually into this national data set by the AIHW-National Perinatal Epidemiology and Statistics Unit (NPESU). Information is included in the NPDC on both live births and stillbirths of at least 400 grams birthweight or at least 20 weeks gestation, except in Western Australia, where the births included were at least 20 weeks gestation or, if gestation was unknown, the birthweight was at least 400 grams.

Summary of key issues

  • The National Perinatal Data Collection (NPDC) provides national information on the pregnancy and childbirth of mothers, and the characteristics and outcomes of their babies.
  • It contains information on all births in Australia in hospitals, birth centres and the community.
  • It includes information on the Indigenous status of the mother only. Since 2005, all jurisdictions have collected information on Indigenous status of the mother in accordance with the Perinatal National Minimum Data Set (NMDS).
  • Neonatal deaths collected as part of the NPDC may be incomplete.
  • The Australian Capital Territory data contain a relatively high proportion of New South Wales residents who gave birth in the Australian Capital Territory.
Institutional environment:

Data in the NPDC include data collected as part of the Perinatal NMDS and supplied by state and territory health authorities to the Australian Institute of Health and Welfare (AIHW). The NPESU is a collaborating centre of the AIHW. States and territories supplied these data under the terms of the National Health Information Agreement:

National Health Information Agreement

Data specifications for the NPDC are documented in the AIHW online metadata repository METeOR – AIHW online metadata repository

Perinatal National Minimum Data Set (NMDS)

Maternity Information Matrix <>.

The AIHW is Australia’s national agency for health and welfare statistics and information. The role of the AIHW is to provide information on Australia’s health and welfare, through statistics and data development that inform discussion and decisions on policy and services.

The AIHW works closely with all state, territory and Australian government health authorities in collecting, analysing and disseminating data. The AIHW is an independent statutory authority within the Health portfolio, and is responsible to the Minister for Health. The AIHW is governed by a board, which is accountable to the Parliament of Australia through the Minister.

Timeliness: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 were requested to be submitted on 30 April 2013. Three jurisdictions supplied required data by this date. Final and useable data was received from all jurisdictions by 30 September 2013. Data are published in the Australia’s mothers and babies report in November/December each year, about two years after the end of the data collection period. The National Health Information Standards and Statistics Committee agreed that jurisdictions would move to financial year data collection from July 2013.

The AIHW-NPESU provides a variety of products that draw upon the NPDC. Published products available are:
• Australia’s mothers and babies annual report
• Indigenous mothers and their babies reports
• National core maternity indicators reports.
• Children’s Headline indicators reports.

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

Data for selected indicators are also published biennially in reports such as Australia’s Health, the Aboriginal and Torres Strait Islander Health Performance Framework report, A Picture of Australia’s Children, and the Overcoming Indigenous Disadvantage report.

The latest publication on the National Perinatal Data Collection is Australia’s mothers and babies 2011. This is the twenty-first annual report on pregnancy and childbirth in Australia providing national information on women who gave birth and the characteristics and outcomes of their babies.

Interpretability:Supporting information on the use and quality of the NPDC are published annually in Australia’s mothers and babies (Chapter 1), and available in hard copy or on the AIHW website. Comprehensive information on the quality of Perinatal NMDS elements are published in Perinatal National Minimum Data Set compliance evaluation 2006 to 2009 (Donnolley & Li 2012). Readers are advised to read caveat information to ensure appropriate interpretation of data. Metadata information for the NPDC are published in METeOR, the National health data dictionary and the Maternity Information Matrix.

The NPDC comprises data items as specified in the Perinatal National Minimum Data Set plus additional items collected by the states and territories. The purpose of the NPDC is to collect information at birth 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 all live births and stillbirths of at least 400 grams birthweight, or at least 20 weeks gestation. It 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, sex, gestational age at birth, birthweight and neonatal morbidity and fetal 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 items, data development work on existing perinatal METeOR items and the development of new perinatal items. The scope of the NPDC has not changed. Many of the core data elements have also not changed since the beginning of the data collection in 1991. Definitions and data domains of some individual data elements have changed over time in response to data development; however, in many cases, data can be mapped to create a consistent time series.

New data elements introduced into the NPDC will not be available for the entire period. Developments to the Perinatal NMDS are under way to include additional data elements. Collection of data for alcohol use in pregnancy is under development. Indigenous status of the baby has been added to the NMDS, with data collection beginning from 1 July 2012. The number of antenatal care visits, postpartum perineal status, type of analgesia administered, type of anaesthesia administered have been added to the NMDS for collection from 1 July 2012.

Due to the time delay between collection of data by the state and territory perinatal data collections and their inclusion into the NPDC, these items will not appear in published data until after 2013. Enhancement of perinatal data is a priority for the Council of Australian Governments.


Inaccurate responses may occur in all data provided to the AIHW-NPESU. The AIHW-NPESU does not have direct access to perinatal records to determine the accuracy of the data provided. However, the AIHW-NPESU undertakes validation on receipt of data. Data received from states and territories are checked for completeness, validity and logical errors. Potential errors are queried with jurisdictions, and corrections and resubmissions are made in response to these edit queries. The AIHW-NPESU does not adjust data to account for possible data errors.

Errors may occur during the processing of data by the states and territories or at the AIHW-NPESU. Processing errors before data supply may be found through the validation checks applied by the AIHW-NPESU.

Before publication, data are referred back to jurisdictions for checking and review. The AIHW-NPESU does not adjust the data to correct for missing values. Note that because of data editing and subsequent updates of state/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 (AIHW 2012). All states and territories have a data item to record Indigenous status of the mother on their perinatal form, although there are some differences among the jurisdictions. For 2011, data on the baby’s Indigenous status were available from New South Wales, Victoria, Queensland, Tasmania, the Australian Capital Territory and the Northern Territory. 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 2011 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.


NPDC data are reported and published annually by the AIHW. While definitions and data domains of some individual data elements have changed over time in response to data development, in many cases it is possible to map coding changes to make meaningful comparisons over time.

The other national data sources on perinatal data are the Australian Bureau of Statistics (ABS) and the AIHW 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 at least 20 weeks gestation where birthweight is unknown. The 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.

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