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National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2018; Quality Statement

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term689648
Registration status:Help on this termIndigenous, Endorsed 07/02/2018

Relational attributes

Indicators linked to this Quality statement:Help on this term

National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2018 Indigenous, Archived 31/07/2018

National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2019 Indigenous, Endorsed 31/07/2018

Data quality

Quality statement summary:Help on this term

The data used to calculate this indicator are from the National Perinatal Data Collection (NPDC), which is a national population-based cross-sectional data collection of pregnancy and childbirth.

Data supplied for the NPDC consists of the Perinatal National Minimum Data Set (NMDS), as well as a series of additional data items. The Perinatal NMDS is an agreed set of standardised perinatal data elements for mandatory supply by states and territories to support national reporting. 

The Perinatal NMDS includes two standardised data elements on tobacco smoking during pregnancy for births from July 2010: smoking during the first 20 weeks of pregnancy, and smoking after 20 weeks of pregnancy. All states and territories reported these items in 2015 and data are complete for 98.4% of mothers.

Definitions and methods used for data collection of smoking during pregnancy differ among the jurisdictions and therefore comparisons between states and territories should be made with caution.

The NPDC has included information on the Indigenous status of the mother in accordance with the Perinatal NMDS since 2005. 

In 2015, 0.1% of mothers who gave birth had missing information on Indigenous status.

Remoteness data for 2012 and subsequent years are not directly comparable with remoteness data for previous years.

Institutional environment:Help on this term

Data for this indicator were provided by the Australian Institute of Health and Welfare (AIHW). The 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 corporate Commonwealth entity established in 1987, governed by a management Board, and accountable to the Australian Parliament through the Health portfolio. For further information about the AIHW, see the AIHW website.

Data for the NPDC were supplied to the AIHW by state and territory health authorities. 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

Timeliness:Help on this term

The reference period for the data is the calendar year 2015.

Collection of data for the NPDC is annual.

Accessibility:Help on this term

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

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

Data for this indicator are published in a number of reports, including annually in the National Indigenous Reform Agreement (which is available on the Productivity Commission website) and the Australia’s mothers and babies reports, and biennially in reports such as the Aboriginal and Torres Strait Islander Health Performance Framework report and the Overcoming Indigenous Disadvantage reports.

Interpretability:Help on this term

Supporting information on the quality and use of the NPDC, including information on the quality of Indigenous status data, is published annually in the AIHW’s Australia’s mothers and babies report (Appendixes A and D in the 2015 edition) (AIHW 2017) and in the data quality statement for the NPDC.

Readers are advised to read caveat information to ensure appropriate interpretation of the performance indicator.

Metadata information for this indicator are published in the AIHW’s online metadata repository, METeOR. Metadata information for the NPDC are published in the National Health Data Dictionary (NHDD) on METeOR and in the Maternity Information Matrix.

Relevance:Help on this term

The NPDC comprises data items as specified in the Perinatal 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.

The NPDC includes all relevant data elements for this indicator. Smoking status of the mother and Indigenous status of the mother are data elements in the Perinatal NMDS.

In the NPDC, mother’s smoking status is self-reported.

Nationally agreed data items on smoking during the first 20 weeks of pregnancy and smoking after 20 weeks of pregnancy were added to the Perinatal NMDS from July 2010. Standardised data for these items were implemented by all states and territories in 2012 except Tasmania which had partial implementation until January 2013. In 2015, data were available for all states and territories. Due to differences in definitions and methods used for data collection, care must be taken when comparing across jurisdictions. Note that in Western Australia, smoking status was determined at multiple locations and times and is therefore difficult to report accurately at time of birth.

Before 2012, non-standard data provided voluntarily to the NPDC were used when information from standard data items was not available or where standard data items did not exist. Definitions used for non-standard data items on smoking during pregnancy differed among the jurisdictions. From 2005 onwards, all states and territories asked at least one smoking question as part of their routine perinatal data collections, except Victoria which collected this information from 2009 onwards.

While each jurisdiction has a unique form for collecting perinatal data on which the format of the Indigenous status question and recording categories vary slightly, all forms have included the Perinatal NMDS item on Indigenous status of the mother from 2005.

Nationally, the proportion of mothers who were Indigenous ranged from 3.5–4.3% of all women who gave birth between 2002 and 2015. This varied by jurisdiction—for example, in 2015, the proportion of mothers who were Indigenous ranged from around 1% in Victoria to 33% in the Northern Territory.

For records where Indigenous status was not stated, data were excluded from Indigenous and non-Indigenous analyses.

Data for this indicator exclude women whose smoking status was not stated and include women who quit smoking during pregnancy.

Analysis excludes non-Australian residents, residents of external territories and where state/territory of usual residence was not stated.

Analysis by state/territory and remoteness is based on the usual residence of the mother.

Reporting by remoteness is in accordance with the Australian Statistical Geography Standard (ASGS).

Accuracy:Help on this term

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 prior to 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.

This indicator is calculated from data that has been reported to the AIHW. Before publication, data are referred back to jurisdictions for checking and review. The numbers reported for this indicator may differ from those in reports published by the states and territories for the following reasons:

  • data editing and subsequent updates of state/territory databases after the supply of data to the AIHW
  • data are reported by state/territory of usual residence rather than state/territory of birth.

The geographical location code for the area of usual residence of the mother is included in the Perinatal NMDS. Only 0.3% of records were for Australian non-residents or could not be assigned to a state or territory of residence. There is no scope in the data element ‘Area of usual residence of mother’ to discriminate temporary residence of mother for the purposes of accessing birthing services from usual residence. The former may differentially impact populations from Remote and Very remote areas, where services are not available locally.

Data presented by Indigenous status are influenced by the quality and completeness of Indigenous identification of mothers which may differ across jurisdictions. In 2015, information on the Indigenous status of the mother was missing for 0.1% of mothers who gave birth. Jurisdictional differences in the level of data missing for Indigenous status ranged from 0.0% to 1.9%, and there may also be differences in the rates of Indigenous under-identification. Therefore, jurisdictional comparisons of data by Indigenous status should be made with caution.

Nationally, smoking status was not stated for 1.5% of all mothers in 2014 (1.4% of Indigenous mothers and 1.6% of non-Indigenous mothers).

Coherence:Help on this term

Data for this indicator are published annually by the AIHW in the Australia’s mothers and babies reports (e.g. AIHW 2017); and biennially in reports such as the Aboriginal and Torres Strait Islander health performance framework (e.g. AHMAC 2017), and Overcoming Indigenous disadvantage (e.g. SCRGSP 2016). The numbers presented in these publications may differ slightly from those presented here as this measure is reported by state and territory of usual residence, and presents both crude rates and age-standardised rates.

Data presented for this indicator for 2015 may not be consistent or comparable with data for earlier years. The introduction of the new standardised items progressively from July 2010 may have resulted in higher rates of smoking being reported, particularly for jurisdictions that previously only collected smoking status information at the first antenatal visit. For these jurisdictions, women who started smoking in pregnancy after the first antenatal visit and women who ceased smoking prior to their first antenatal visit may not have been counted as smokers whereas, under the standard data items, these women would be counted as smokers. Given the different timing and instruments for data collection on smoking during pregnancy, comparisons over time and between states and territories should be interpreted with caution.

Changing levels of Indigenous identification over time and across jurisdictions may also affect the accuracy of compiling a consistent time series in future years.

The NPDC has collected information on the Indigenous status of the mother in accordance with the Perinatal NMDS since 2005.

In 2011, the ABS updated the standard geographical framework from the Australian Standard Geographical Classification (ASGC) to the ASGS. NPDC data by remoteness for 2011 and earlier years are based on the ASGC, while data for 2012 onwards are based on the ASGS. The AIHW considers the change to be a break in series when applied to remoteness data supplied for this indicator; therefore, remoteness data for 2012 are not directly comparable with data for previous years.

For data reported from 2012, the standard population used for the calculation of age-standardised rates for mothers was amended from the Australian female population who gave birth in each reporting period to the Australian female Estimated Resident Population (ERP) aged 15–44 as at 30 June 2001. Data back to the baseline reporting year (2007) were revised accordingly.

Source and reference attributes

Submitting organisation:Help on this term

Australian Institute of Health and Welfare

Reference documents:Help on this term

AIHW (Australian Institute of Health and Welfare) 2017. Maternal and perinatal data. Viewed 3 February 2017, http://www.aihw.gov.au/mothers-and-babies/

Relational attributes

Related metadata references:Help on this term

Supersedes National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2015-16; Quality Statement Indigenous, Archived 07/02/2018

See also National Perinatal Data Collection, 2015: Quality Statement AIHW Data Quality Statements, Archived 02/08/2018

See also National Perinatal Data Collection, 2016: Quality Statement AIHW Data Quality Statements, Endorsed 02/08/2018

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