Australian Bureau of Statistics
3301.0 - Births, Australia, 2011 Quality Declaration
Previous ISSUE Released at 11:30 AM (CANBERRA TIME) 25/10/2012
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6 The scope of the statistics exclude:
7 The scope for each reference year of the Birth Registrations collection include:
8 Birth records received by ABS during the March quarter 2012 which were initially registered in 2011 (but not fully completed until 2012) were assigned to the 2011 reference year. Any registrations relating to 2011 which were received by ABS from April 2012 were assigned to the 2012 reference year.
9 Prior to 2007, the scope for the reference year of the Birth Registrations collection included:
Coverage of birth statistics
10 Ideally, for compiling annual time series, the number of events (births) should be recorded as all those occurring within a given reference period such as a calendar year. Due to lags in registration of births and the provision of that information to the ABS from state and territory Registrars of Births, Deaths and Marriages, data in this publication are presented on a year of registration basis.
11 In effect there are three dates attributable to each birth registration:
12 Data in this publication are presented according to date of registration, unless otherwise stated. The registration date differs between states and territories, and should be taken into account when analysing birth statistics:
13 Nuptiality relates to the registered marital status of the parent(s) of the child at the time of birth. Confinements and births are classified as:
14 Ex-nuptial births and confinements are further classified as paternity acknowledged (where the father signed the birth registration form) or paternity not acknowledged (where the father did not sign the birth registration form).
15 This issue of Births, Australia includes data cubes containing birth and fertility statistics on the Australian Standard Geographical Classification (ASGC), the Australian Statistical Geography Standard (ASGS) and the Standard Australian Classification of Countries (SACC), Second Edition.
16 Since July 2011, the ABS has been progressively transitioning from the Australian Standard Geographical Classification (ASGC) to the Australian Statistical Geography Standard (ASGS). The ASGS is a hierarchical classification system that defines more stable, consistent and meaningful areas than the ASGC. Future issues of this publication will only contain birth statistics on the ASGS boundaries.
17 The Standard Australian Classification of Countries (SACC) (Second Edition) groups neighbouring countries into progressively broader geographical areas on the basis of their similarity in terms of social, cultural, economic and political characteristics.
18 For further information, refer to Australian Standard Geographical Classification (ASGC) (cat. no. 1216.0), Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2011 (cat. no. 1270.0.55.001) and Standard Australian Classification of Countries (SACC), Second Edition (cat. no. 1269.0).
19 Registration of births is the responsibility of state and territory Registrars of Births, Deaths and Marriages and is based on data provided on an information form completed by the parent(s) of the child. This form is the basis of data provided to the ABS by the Registrars for compilation into aggregate statistics in this publication. Most data items are collected in all states and territories and therefore statistics at the national level are available for most characteristics. Some states collect additional information.
20 Hospitals and birth clinics notify state and territory registries of recent births on a regular basis. For births where a notification has been received by a registry, but has not been registered within the prescribed time period, a reminder letter is sent to the parent(s) of the child.
State and territory data
21 As a result of an amendment made in 1992 to section 17(a) of the Acts Interpretation Act 1901-1973 (Cwlth), the Indian Ocean territories of Christmas Island and Cocos (Keeling) Islands have been included as part of geographic Australia, hence another category of the state and territory classification has been created. This category is known as 'Other Territories' and includes Christmas Island, the Cocos (Keeling) Islands and Jervis Bay Territory.
22 Prior to 1993, births to mothers usually resident in Christmas Island or Cocos (Keeling) Islands were included with Off-Shore Areas and Migratory in Western Australia, while births to mothers usually resident in Jervis Bay Territory were included with the Australian Capital Territory. In 2011, there were 32 births to mothers usually resident in Jervis Bay Territory, Christmas Island or the Cocos (Keeling) Islands.
23 Birth statistics for states and territories have been compiled and presented according to the state or territory of usual residence of the mother regardless of where in Australia the birth occurred and was registered, except where otherwise stated. In the following table, data are presented on a state or territory of registration basis. Births which took place outside Australia are excluded from the statistics. Births to mothers who were usual residents of Australia's Other Territories (Christmas Island, Cocos (Keeling) Islands and Jervis Bay Territory) are registered in other Australian states.
24 In 2011, there were 308 births registered in Australia to women who usually lived overseas. These have been included in this publication with state or territory of usual residence classified according to the state or territory in which the birth was registered.
Sub-state/territory fertility rates
25 Age-specific and total fertility rates for sub-state/territory regions (for example, Statistical Divisions) presented in data cubes released with this publication are average rates for three years ending in the reference year. Rates for Australia and the states and territories in all other tables are based on single years of birth registration data.
26 In compiling birth statistics, the ABS employs a variety of measures to improve the quality of the birth registrations collection. While every opportunity is taken to ensure that the highest quality of statistics are provided, the following are known issues associated with the statistics included in this publication.
Interval between occurrence and registration of births
27 For the most part, statistics in this publication refer to births registered during the calendar year shown. There is usually an interval between the occurrence and registration of a birth (referred to as a registration 'lag') and as a result, some births occurring in one year are not registered until the following year or later. This can be caused by either a delay by the parent(s) in submitting a completed form to the registry, or a delay by the registry in processing the birth. Births which occur in November and December are also likely to be registered in the following year.
28 Of the 301,617 births registered in 2011, 87.7% occurred in 2011, while 9.1% occurred in 2010 and the remainder (3.2%) occurred in 2009 or earlier years.
Effects of registration lags on plurality statistics
29 It has been observed in recent years that there is a small number of twin and higher order births from the same confinement that are registered in different reference years. Due to this reason, the number of twin and higher order births registered in a reference year may not exactly match the number of confinements registered in that year. For more information on the coverage of a reference year, see paragraph 8.
Recent registration lags in Queensland
30 As a result of changes in the timeliness of registration of births in Queensland, care should be taken when interpreting changes in Queensland births between 2005 and 2010. This lag has reduced in recent years, indicating potential improvements in the timeliness of registration of births in Queensland.
31 The December quarter 2009 also saw the Queensland Registry of Births, Deaths and Marriages devoting significant time and resources to follow-up and finalise birth registrations where there was previously incomplete information. As part of the 'Retrospective Births Project', 1,780 births were registered, with approximately 40% registered as Aboriginal and Torres Strait Islander births (see paragraph 40 for more information). This project is now complete.
Previously unprocessed New South Wales births
32 Questions have been raised over the completeness of the New South Wales (NSW) birth counts in recent years. In response to these concerns the ABS, in conjunction with the NSW Registry of Births, Deaths and Marriages, has undertaken an investigation which has led to the identification of an ABS systems processing error. The ABS acknowledges that this has resulted in previous under coverage of births in NSW. Data for 2011 have been corrected to ensure that NSW birth and fertility statistics released in this publication are correct. The ABS understands that this error has occurred since 2005 and will be undertaking further investigations to determine the appropriate action that is required. See Technical Note: Effect of previously unprocessed New South Wales births for more information.
Tasmanian birth registrations
33 The Tasmanian Births, Deaths and Marriages Registration Act 1999 requires hospitals, doctors, midwives or other responsible persons to provide the Tasmanian Registrar with a list of babies born containing basic information such as date of birth and sex of the baby. In the case of a live birth, the birth notification must be provided within 21 days of the birth. These notifications have been provided to the ABS since 2002 and are also used in producing quarterly population estimates.
34 Under the Act, the birth of a child must also be registered by lodging a birth registration statement with the Registrar within 60 days after the date of birth of the child. Once the parent(s) submits the birth registration statement, the record is updated and the Registrar provides ABS with a complete registration record. Where a match between a birth notification and birth registration statement is identified, the record is quality assured to ensure completeness of the record.
35 Prior to 2007, records for which a birth registration form was not received were coded as 'ex-nuptial, paternity not acknowledged'. As a result, the number of ex-nuptial births in Tasmania may be overstated for 2002 to 2006. From 2007, these records have been excluded from all nuptiality statistics. In 2011, there were 177 unmatched birth registration forms.
Aboriginal and Torres Strait Islander births and fertility rates
36 The ABS Birth Registrations collection records a birth as being an Aboriginal and Torres Strait Islander birth where at least one parent reported themselves as being an Aboriginal person, Torres Strait Islander, or both on the birth registration form. Therefore, Aboriginal and Torres Strait Islander births may be attributed to either:
37 There are several data collection forms on which people are asked to state whether they are Aboriginal and/or Torres Strait Islander people. Due to a number of factors, the results are not always consistent. The likelihood that a person will report, or be recorded, as an Aboriginal and/or Torres Strait Islander person on a specific form is known as their propensity to identify. Propensity to identify can be thought of as the proportion of the total, unknown, number of Aboriginal and Torres Strait Islander people who are reported and were recorded as such on a specific form.
38 Propensity to identify and be recorded as an Aboriginal and/or Torres Strait Islander person is determined by a range of factors, including how the information is collected; who completes the form; the perceptions of how the information will be used; education programs about reporting as an Aboriginal and/or Torres Strait Islander person; and cultural aspects and feelings associated with reporting as an Aboriginal and/or Torres Strait Islander person.
39 Data presented in this publication may therefore underestimate the level of Aboriginal and Torres Strait Islander births and fertility in Australia. Lags in registrations may also affect reliability of measures of Aboriginal and Torres Strait Islander fertility. Caution should be exercised when interpreting Aboriginal and Torres Strait Islander data presented in this publication, especially with regard to year-to-year changes.
Recent registration lags in Queensland
40 As described in paragraph 31, the Queensland Registry of Births, Deaths and Marriages undertook a 'Retrospective Births Project' during 2009 resulting in the registration of births where there was previously incomplete information. A significant proportion of these births were registered as Aboriginal and Torres Strait Islander births, which has affected fertility data in Queensland for 2009 (see Chapter 4: Effect of delayed birth registrations in Australia in the 2009 issue of Births, Australia (cat. no. 3301.0) for more information). Caution should be exercised when interpreting year-to-year changes for Queensland data.
Registration of Aboriginal and Torres Strait Islander births in New South Wales
41 Since 2006, Indigenous status of the mother and father for births registered in New South Wales has not been consistent with other jurisdictions. Specifically, where one parent is an Aboriginal and/or Torres Strait Islander person, the other parent will be processed as either 'Aboriginal and Torres Strait Islander' or 'Not stated'. Further, where one parent is 'Non-Indigenous', the other parent will also be processed as 'Non-Indigenous' or 'Not stated'. The Indigenous status of the child, where the birth is registered in New South Wales, is derived from the Indigenous status of each of the parents. Indigenous status of births registered in New South Wales should therefore be interpreted with caution. The ABS has been advised that this matter is being investigated as part of other processing system developments underway.
42 ABS have investigated recent year-to-year variability in the number of births of Aboriginal and Torres Strait Islander peoples. In 2011, 146 births were to mothers who reported themselves as being an Aboriginal and/or Torres Strait Islander person, and who were born overseas. Since 2007, these instances have accounted for between 1% and 3% of births to Aboriginal and/or Torres Strait Islander mothers. Of these births in 2011, 58% were to mothers born in neighbouring countries in the Pacific, such as New Zealand, Samoa and Papua New Guinea, and the majority of these (54 births) were to mothers who reported themselves as being Torres Strait Islander, or both Aboriginal and Torres Strait Islander on the birth registration form. This may indicate that these mothers are seeking to report their Pacific Islander ancestry (for which provision is not made in the Birth Registration Statement forms in Australia) rather than reporting to be Torres Strait Islanders. However, the 12 births to mothers born in Papua New Guinea in 2011 who reported being Torres Strait Islanders may be correctly recorded. The ABS continues to monitor this and work with Registries to improve quality assurance around these data.
43 This publication reports on the number and characteristics of Aboriginal and Torres Strait Islander births and fertility rates in each state and territory, excluding the Australian Capital Territory and Other Territories. Aboriginal and Torres Strait Islander data for the Australian Capital Territory and Other Territories are not analysed separately due to small numbers, but are included in totals for Australia.
44 The populations used to calculate Aboriginal and Torres Strait Islander fertility rates in this publication are estimates and projections of the Aboriginal and Torres Strait Islander female population aged 15–49 years, based on results of the 2006 Census of Population and Housing. For more information, see Experimental Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 1991 to 2021 (cat. no. 3238.0).
45 Estimates of annual numbers of Aboriginal and Torres Strait Islander births in Australia are available from two collections:
46 In addition to these collections, it is possible to derive indirect estimates and projections of numbers of Aboriginal and Torres Strait Islander births, based on 2006 Census-based Aboriginal and Torres Strait Islander population estimates:
Edits and imputations
47 During edit processes for the Birth Registrations collection, some items are corrected where they conflict with other known information. Missing data for some data items are imputed when appropriate. In 2011, there were 701 birth registrations for which place of usual residence was imputed, and 18 registrations for which sex was not reported and was imputed.
Parity (previous children of mother)
48 Parity refers to the number of (live) births that a woman has had. Birth order refers to whether a birth is the first, second, third or higher-order birth of the parent. In registering births, information is collected on the number of previous children born to a mother.
49 Changes in ABS processing of birth registrations from 2007 have resulted in the availability of improved information on previous births to mothers. Prior to 2007, ABS published information on previous births of the mother from the current relationship only, for all states and territories. From 2007 onwards, data on previous births for all relationships (both current and previous, if any) of the mother are collected for all states and territories, excluding Victoria and Queensland. Due to the high proportion (28%) of confinements in Tasmania in 2011 for which no information on previous children of the mother was available, data for Tasmania should be interpreted with caution. As a result of these inconsistencies, Australian parity figures in this publication exclude data for Victoria, Queensland and Tasmania.
50 These data are collected as a result of the increasing demand for parity data for analysis and dissemination. For more information on the use of parity data and collection methods associated with these statistics, see Corr, P. and Kippen, R. 2006, The Case for Parity and Birth-Order Statistics, Australia and New Zealand Journal of Statistics, vol. 48, no. 2, pp. 171-200.
51 As a result of the above changes, data on previous births for 2007 onwards are not comparable with data for earlier years. However, the improved information indicates that the prevalence of first births (that is, mothers with no previous children) was overestimated prior to 2007, while numbers of mothers with two or more previous children were underestimated.
Age of parent(s)
52 During birth registration processing since 2007, discrepancies were identified between age of mother data as provided to the ABS by the Registrars and age of mother derived from date of birth of mother. In 2011, there were 1,469 records (0.5% of all confinements) for which the derived age of mother was found to be inconsistent with the reported age. For these records, the derived age of mother was used. The same process was applied to information on age of father, for which 1,246 records were affected. For years prior to 2007, median age may have been overstated.
53 The Census and Statistics Act 1905 provides the authority for the ABS to collect statistical information, and requires that statistical output shall not be published or disseminated in a manner that is likely to enable the identification of a particular person or organisation. This requirement means that the ABS must take care and make assurances that any statistical information about individual respondents cannot be derived from published data.
54 Where necessary, tables in this publication have had small values suppressed or randomised to protect confidentiality. As a result, sums of components may not add exactly to totals.
55 Calculations as shown in the commentary sections of this publication are based on unrounded figures. Calculations using rounded figures may differ from those published. Where figures have been rounded in tables, discrepancies may occur between sums of component items and totals.
56 ABS publications draw extensively on information provided freely by individuals, business, governments and other organisations. The efforts of Registries of Births, Deaths and Marriages to improve the data quality, coverage and timeliness of birth registration information, processes and systems are noted and valued by the ABS. Their continued cooperation is very much appreciated; without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.
ADDITIONAL STATISTICS AVAILABLE
57 ABS products and publications are available free of charge from the ABS website <http://www.abs.gov.au>. Click on Statistics to gain access to the full range of ABS statistical or reference information.
58 As well as the statistics included in this and related publications, the ABS may have other relevant data available on request. Inquiries should be made to the National Information and Referral Service on 1300 135 070.
59 The ABS also issues a daily Release Advice on the website which details the products to be released in the week ahead.
60 Other publications which may be of interest to users include Australia's Mothers and Babies, 2009, Australian Institute of Health and Welfare National Perinatal Statistics Unit, AIHW website <www.aihw.gov.au>. Please note there are differences between the ABS and AIHW birth collections; these are discussed in Appendix: Differences Between Collections included with this publication on the ABS website.
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This page last updated 23 October 2013