National Healthcare Agreement: P01-Proportion of babies born with low birth weight, 2010 QS

Identifying and definitional attributes

• Health, Superseded 08/06/2011

Relational attributes

National Healthcare Agreement: P01-Proportion of babies born with low birth weight, 2010
Health, Superseded 08/06/2011

Data quality

• Birth weight is included in the Perinatal National Minimum Data Set (NMDS) and data are complete for over 99.9% of babies.
• This measure only includes births of at least 20 weeks gestation or 400 grams birthweight. It excludes multiple births and babies with unknown birthweight and the measure may therefore differ slightly from information presented in other publications on low birthweight.
• Since 2005, all jurisdictions provide information on Indigenous status of the mother in accordance with the Perinatal NMDS.
• No formal national assessment has been undertaken to determine completeness of the coverage or identification of Indigenous mothers in the National Perinatal Data Collection (NPDC) or to determine variability between states and territories. The current data have not been adjusted for under-identification of Indigenous status of the mother.
• Area of usual residence of the mother is included in the Perinatal NMDS and data are complete for over 99.9% of mothers.

The Australian Institute of Health and Welfare (AIHW) has calculated this indicator. Data included in the National Perinatal Data Collection (NPDC) are collected as part of a National Minimum Data Set (NMDS) and were supplied by state and territory health authorities to the National Perinatal Statistics Unit (NPSU), a collaborating unit of the AIHW. The state and territory health authorities receive these data from patient administrative and clinical records. This information is usually collected by midwives or other birth attendants. States and territories use these data for service planning, monitoring and internal and public reporting.

The AIHW is an independent statutory authority within the Health and Ageing portfolio, which is accountable to the Parliament of Australia through the Minister. For further information see the AIHW website.

States and territories supplied these data under the terms of the National Health Information Agreement (see link).
http://www.aihw.gov.au/committees/simc/final_nhia_signed.doc

Data specifications for the Perinatal NMDS are documented in the AIHW online metadata repository, METeOR (see link).
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The AIHW provides a variety of products that draw upon the NPDC. Published products available on the AIHW website are:

• Australia’s mothers and babies, annual report
• Indigenous mothers and their babies, Australia 2001-2004
• METeOR – online metadata repository
• National health data dictionary

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

The National Perinatal Data Collection 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 at birth for monitoring pregnancy, childbirth and the neonatal period for both the mother and baby/babies.

The Perinatal NMDS 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 (live or stillbirth), sex, gestational age at birth, birth weight, Apgar score and neonatal length of stay.

The National Perinatal Data Collection provides all relevant data elements of interest for this indicator. Birthweight is a Perinatal NMDS item. In 2007, very few (0.03%) records for live born singleton babies were missing the data for birthweight.

While each jurisdiction has a unique perinatal form for collecting data on which the format of the Indigenous status question and recording categories varies slightly, all systems include the NMDS item on Indigenous status of mother.

No formal national assessment has been undertaken to determine completeness of the coverage of Indigenous mothers in the Perinatal NMDS or to determine variability between states and territories. However, the proportion of Indigenous mothers for the period 1997-2006 has been consistent, at 3.2–3.7% of women who gave birth.  For maternal records (0.1%) where Indigenous status was not stated, data were excluded. Comparisons between states and territories should be interpreted with this caution.

The indicator is presented by Socio-Economic Indexes for Areas (SEIFA) Index for Relative Socio-Economic Disadvantage (IRSD). The data supplied to the National Perinatal Data Collection include a 5-digit code for SLA from all states and territories except Tasmania (which supplies postal area codes). Reporting by remoteness is in accordance with the Australian Standard Geographical Classification (ASGC).

Inaccurate responses may occur in all data provided to the AIHW. The AIHW does not have direct access to perinatal records to determine the accuracy of the data provided. However, the AIHW 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 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. Processing errors prior to data supply may be found through the validation checks applied by the Institute. This indicator is calculated on data that has been reported to the AIHW. Prior to publication, these data are referred back to jurisdictions for checking and review. The AIHW does not adjust the data to correct for missing values. Note that because of data editing and subsequent updates of state/territory databases, and because data are being reported by place of residence rather than place of birth the numbers reported for this indicator differ from those in reports published by the states and territories. The data are not rounded.

The geographical location code for the area of usual residence of the mother is included in the Perinatal NMDS. Less than 0.08% of records 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.

Birthweight is near universally reported. Less than 0.03% of records are missing data.

Data presented by Indigenous status are influenced by the quality and completeness of Indigenous identification of mothers which is likely to differ among jurisdictions. Approximately 0.1% of mothers who gave birth in the reference period had missing Indigenous status information. No adjustments have been made for under-identification or missing Indigenous status information.

Cells have been suppressed to protect confidentiality (where the presentation could identify a person or a single service provider), where rates are highly volatile (for example, the denominator is very small), or data quality is known to be of insufficient quality (for example, where Indigenous identification rates are low).

Data for this indicator are published annually in Australia’s mothers and babies; and biennially in reports such as the Aboriginal and Torres Strait Islander Health Performance Framework Report;The Health and Welfare of Australia’s Aboriginal and Torres Strait Islander Peoples; and the Overcoming Indigenous Disadvantage report. The numbers presented in these publications may differ depending on the inclusion criteria of the data selected to compile them.

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

Source and reference attributes

Relational attributes