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National Indigenous Reform Agreement: PI 08—Tobacco smoking during pregnancy, 2015, Quality Statement

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term593460
Registration status:Help on this termIndigenous, Archived 07/02/2017

Relational attributes

Indicators linked to this Quality statement:Help on this term

National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2015 Indigenous, Archived 18/11/2015

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 items 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. However, 2012 is the first year for which all states and territories reported against these standard items.
  • 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.
  • Since 2005, the NPDC has included information on the Indigenous status of the mother in accordance with the Perinatal NMDS.
  • In 2012, 0.2% of mothers who gave birth had missing information on Indigenous status.
  • Since the last reporting cycle, the standard population used for calculating 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 as at 30 June 2001. Data back to the baseline reporting year (2007) have been revised accordingly.
  • Remoteness data for 2012 are not directly comparable with remoteness data for previous years.
Institutional environment:Help on this term

Data for this indicator were provided by the National Perinatal Epidemiology and Statistics Unit (NPESU) on behalf of 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 www.aihw.gov.au.

Data collected as part of the NPDC were supplied by state and territory health authorities to the AIHW. 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

For the current reporting cycle, NPDC data are provided for the calendar year 2012.

The AIHW is working with jurisdictions on an ongoing basis to improve the capture, quality and timeliness of the data.

Accessibility:Help on this term

The AIHW provides a variety of products that draw upon the NPDC. Published products available on the AIHW website include:

Ad-hoc data from the NPDC 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 information reports (which are available on the Productivity Commission website) and the Australia’s mothers and babies reports, and biennially in the Aboriginal and Torres Strait Islander Health Performance Framework reports 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 and other data items used in the calculation of this indicator, are published annually in Australia’s mothers and babies, which is available on the AIHW website. Comprehensive information on the quality of Perinatal NMDS data 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 the performance indicator.

Metadata information for this indicator are published in the AIHW’s online metadata repository, METeOR. Metadata information for the Perinatal NMDS are also published in METeOR and in the National Health Data Dictionary.

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 Perinatal NMDS is to collect information about births for monitoring pregnancy, childbirth and the neonatal period for both the mother and baby.

The Perinatal NMDS is a specification for data collected about 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, except in 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 NMDS consists of 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, neonatal morbidity and fetal deaths.

In the NPDC, mother’s smoking status is self-reported, and in 2012, data were available for all states and territories.

A program of national data development was completed in 2009 to add nationally agreed data items on smoking during the first 20 weeks of pregnancy and smoking after 20 weeks of pregnancy to the Perinatal NMDS from July 2010. In 2012, standardised data for these items were implemented by all states and territories except Tasmania which had partial implementation. Due to differences in definitions and methods used for data collection, care must be taken when comparing across jurisdictions. Note that in 2012:

  • for Western Australia, smoking status was determined at multiple locations and times and is therefore difficult to report accurately at time of birth
  • for South Australia, women who quit smoking before the first antenatal visit were recorded as smokers
  • for Tasmania, the standard data items have been included in the new electronic data capture system implemented during 2010; however, those hospitals still using the paper-based form did not report these data items.

In 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 do 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 varies slightly, all forms have included the NMDS item on Indigenous status of the mother from 2005. The proportion of mothers who were Indigenous ranged from 3.5%–4.0% of all women who gave birth between 2002 and 2012.

Mothers for whom Indigenous status was not stated have been excluded from analyses for this indicator.

Data provided for this indicator on women who smoked during pregnancy includes women who quit smoking during pregnancy.

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

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

Reporting by remoteness is in accordance with the Australian Statistical Geography Standard (ASGS) for 2012 data and in accordance with the Australian Standard Geographical Classification (ASGC) for years prior to 2012.

Accuracy:Help on this term

Upon receipt of the NPDC data from the states and territories, the NPESU checks it for completeness, validity and logical 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 by the NPESU. Processing errors prior to data supply may be found through the validation checks applied by the NPESU. Prior to publication, the data are referred back to jurisdictions for review. The NPESU does not adjust the data to account for possible data errors or to correct for missing data.

Following the supply of data for this indicator, further minor updates may be made to the data held by the jurisdictions. Such differences in the data are unlikely to produce any detectable change to the indicator. In addition, the 2012 data supplied by Victoria for this indicator were not final data.

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 NPESU
  • data are reported by state/territory of usual residence rather than state/territory of birth.

Data presented by Indigenous status are influenced by the quality and completeness of Indigenous identification of mothers which may differ across jurisdictions. In 2012, 0.2% of mothers who gave birth had missing information about their Indigenous status. Jurisdictional differences in the level of missing data for Indigenous status ranged from less than 0.1% to 1.8%.
Nationally, smoking status was not stated for between 2.6% and 4.4% of Indigenous mothers across the standard smoking data items in 2012.

Coherence:Help on this term

Data presented for 2012 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 2011, the Australian Bureau of Statistics (ABS) updated the standard geographical framework from the ASGC to the ASGS. NPDC data by remoteness for 2007 to 2011 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 remoteness data for previous years.

Since the last reporting cycle, the standard population used for calculating 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 as at 30 June 2001. Data back to the baseline reporting year (2007) have been revised accordingly.

Source and reference attributes

Reference documents:Help on this term

Donnolley N & Li Z 2012. Perinatal National Minimum Data Set compliance evaluation 2006 to 2009. Perinatal statistics series no. 26. Cat. no. PER 54. Sydney: AIHW National Perinatal Epidemiology and Statistics Unit.

Relational attributes

Related metadata references:Help on this term

Supersedes National Indigenous Reform Agreement: PI 08-Tobacco smoking during pregnancy, 2014 QS Indigenous, Archived 17/02/2016

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

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