Data quality and availability of national perinatal mortality data
Some topics in this report may exclude data for selected states and territories for reasons including:
- Data are not currently collected by a state and territory, or are not collected in a format that is comparable with the specifications for the National Perinatal Data Collection (NPDC) or National Perinatal Mortality Data Collection (NPMDC).
- Data are not currently supplied by a state and territory for the NPDC or NPMDC. Data items that are not part of the Perinatal NMDS are not mandatory for provision to the NPDC, and there are currently no Perinatal NMDS items in the NPMDC.
The exclusions for reported data items in the NPDC are summarised in Table 1. These exclusions apply to both the numerator and denominator for rate calculations, and the data presented are not representative of the jurisdictions excluded.
Table 1: Summary of state and territory exclusions in the National Perinatal Data Collection (NPDC) for 2015 and 2016
Victoria (data not currently available according to specifications)
|Body mass index (BMI)(a)||New South Wales (data not provided in 2015, reported in 2016)|
|Previous stillbirth(a)||Queensland, Western Australia and South Australia (data not currently available according to specifications)|
|Number of antenatal visits||Victoria (collection of this data item commenced in Victoria from July 2015; however, implementation was not fully complete at all sites until 2016)|
(a) These data items are not currently part of the Perinatal NMDS and are not mandated for provision to the NPDC.
Detailed information on completeness for all data items in the NPMDC is available in the interactive data visualisation below by jurisdiction for 2013 to 2016.
Definitions for the terms used to quantify completeness:
- Supplied – Stated: supplied an appropriate value for a proportion of records for the data item during specified collection year/s
- Not supplied/stated: proportion of values supplied as not stated or missing, where a jurisdiction has either supplied appropriate values for a portion of records or did not supply any value for all records for the data item during the specified collection year/s.
Preliminary data on perinatal deaths is available through the National Perinatal Data Collection and reported in the Australia’s mothers and babies publication series.
The AIHW has established a separate, enduring National Perinatal Mortality Data Collection to obtain complete information on these deaths which contains annual perinatal deaths data from 2013.
Data on stillbirths and neonatal deaths are provided to the NPDC by jurisdictions as a subset of the larger cohort of all babies born in the same collection period. These preliminary data on stillbirths and neonatal deaths are made available to the public approximately 18 months after the end of the collection period.
Because these data are supplied to the AIHW often prior to completion of all Jurisdictional Mortality Review Committee reports, the data is not as comprehensive as that supplied to the NPMDC, particularly pertaining to PSANZ classification regarding the cause of death and contributory factors.
These preliminary data may also not include neonatal deaths for babies transferred to another hospital, re-admitted to hospital after discharge or who died at home after discharge.
Data provided to the NPMDC may vary from the preliminary data reported by the NPDC due a variety of factors. Such factors include the inclusion of babies transferred to another hospital, re-admitted to hospital after discharge or who died at home after discharge; or cases where not enough detail was able to be provided by the jurisdiction to enable linkage of a particular death in the NPMDC back to the corresponding record in the NPDC.
Quality of data for reporting Indigenous status
Indigenous status is a measure of whether a person identifies as being of Aboriginal and/or Torres Strait Islander origin. Indigenous status of the mother has been a mandatory data item in the Perinatal NMDS since its inception in 1997, but applying the data item to the baby was introduced to the NMDS for collection for the first time in the 2012–13 reference year (from 1 July 2012).
For 2015 and 2016, data on the baby’s Indigenous status was provided by all states and territories. This item, when used in conjunction with the mother’s Indigenous status, is a better baseline measure of health for all Indigenous children. However, the outcomes of babies of Indigenous women remain a key data resource for assessing provision of antenatal care in pregnancy and other interventions before or during pregnancy.
Unless otherwise stated, data for babies are based on the Indigenous status of the mother.
Comparing NPMDC data with ABS registrations of death data
Perinatal death data reported by the Australian Bureau of Statistics (ABS) are not directly comparable with the NPMDC and NPDC data contained in this report. Variation in the number of perinatal deaths reported by the ABS and NPMDC can be seen in Table 2.
While the definitions of stillbirth and neonatal death are the same, ABS data are sourced from state and territory registrars of Births, Deaths and Marriages; while data from the NPMDC and NPDC contained in this report are sourced from midwives, and other staff, who collect information from mothers and perinatal administrative and clinical record systems.
It is the responsibility of the parents to register a birth with Births, Deaths and Marriages however some perinatal deaths may not be recorded when notifications are not registered by the parents. A delay in registrations is often seen, particularly for stillbirths, with the original date of death often being many years prior to the date of registration. This means the accuracy of the number of perinatal deaths reported by the ABS for a particular year often improves over time.
Table 2: Number of perinatal deaths reported by Australian Bureau of Statistics and the National Perinatal Mortality Data Collection, Australia, 2013–2016
|Year||NPMDC Stillbirths||ABS Stillbirths||NPMDC Neonatal deaths||ABS Neonatal deaths|
Note: ABS stillbirths and neonatal deaths are reported by the year in which the death occurred (ABS 2018, Customised report).
For more information on perinatal deaths data collected by the ABS, visit the perinatal deaths page at the Australian Bureau of Statistics.