QUALITY DECLARATION - SUMMARY

INSTITUTIONAL ENVIRONMENT

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.

Birth statistics published by the ABS are sourced from birth registration systems administered by state and territory Registrars of Births, Deaths and Marriages, based on data provided on a registration form completed by the parent(s) of the child. Registration of births is compulsory in Australia under relevant state/territory legislation.

RELEVANCE

Birth statistics are one of the components in the production of estimates of natural increase (excess of births over deaths) used as a component of population change in the calculation of population estimates of Australia and the states and territories. The primary uses of population estimates are in the determination of seats in the House of Representatives for each state and territory, as well as in distribution of Australian Government funds to state, territory and local governments. Population estimates are also used for a wide range of government, business and community decisions, both directly and indirectly, by contributing to a range of other social and economic indicators.

Birth statistics are also essential in the analysis of fertility in Australia, and inform on the population's ability to reproduce itself. Trends in fertility are used in the development of assumptions on future levels of fertility for population projections.

Births, Australia (cat. no. 3301.0) contains statistics for births and fertility in Australia. Data refer to births registered during the calendar year shown, unless otherwise stated. Statistics on demographic characteristics of the parent(s) such as age, place of usual residence, marital status, Indigenous status and country of birth are included.

Births data include:

• all live born births registered in Australia that have not been previously registered;
• births to temporary visitors to Australia (including visitors from Norfolk Island);
• births occurring within Australian Territorial waters;
• births occurring in Australian Antarctic Territories and other external territories (excluding Norfolk Island);
• births occurring in transit (i.e. on ships or planes) if registered in the Australian state or territory of 'next port of call';
• births to Australian nationals employed overseas at Australian legations and consular offices (i.e. children born overseas to Australian diplomats or their families); and
• births that occurred in earlier years that have not been previously registered (late registrations).

Births data exclude:

• still births/fetal deaths (these are accounted for in perinatal death statistics published in Perinatal Deaths, Australia (cat. no. 3304.0) and previously, in Causes of Death, Australia (cat. no. 3303.0));
• adoptions, sex changes, legitimations and corrections;
• births to foreign diplomatic staff; and
• births occurring on Norfolk Island.

TIMELINESS

Birth records are provided electronically to the ABS by individual state/territory Registrars on a monthly basis for compilation into aggregate statistics on a quarterly and annual basis.

Quarterly estimates of births on a preliminary basis are published five to six months after the reference period in Australian Demographic Statistics (cat. no. 3101.0) and revised 21 months after the end of each financial year. Annual estimates on a year of registration basis are generally published within ten months of the end of the reference year in Births, Australia (cat. no. 3301.0).

One dimension of timeliness in birth registrations data is the interval between the occurrence and registration of a birth. 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 (for example, due to follow up activity due to missing information on the form, or resource limitations).

ACCURACY

Information on births is obtained from a complete enumeration of births registered during a specified period and is not subject to sampling error. However, births data sources are subject to non-sampling error which can arise from inaccuracies in collecting, recording and processing the data.

Sources of non-sample error include:

• incompleteness of an individual record at a given point in time;
• incompleteness of the dataset (e.g. impact of registration lags, processing lags and duplicate records and births that are never registered); and
• lack of consistency in the application of questions or forms used by data providers, both through time and between different jurisdictions.

Every effort is made to minimise error by working closely with data providers, the careful design of forms, training of processing staff, and efficient data processing procedures.

COHERENCE

The international standards and recommendations for the definition and scope of birth statistics in a vital statistics system are set out in the Principles and Recommendations for a Vital Statistics System Revision 2, published by the United Nations Statistical Division (UNSD). Consistent with the UNSD recommendations, the ABS defines a birth as the complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy, which after such separation, breathes or shows any other evidence of life, such as beating of the heart, pulsation of the umbilical cord or definite movement of voluntary muscles, whether or not the umbilical cord has been cut or the placenta is attached; each product of such a birth is considered liveborn. In addition, the UNSD recommends that the births to be counted include all births "occurring in every geographic area and in every population group comprising the national area". For Australia, this includes all births occurring within Australia as defined by the Australian Standard Geographical Classification (ASGC) or Australian Statistical Geography Standard (ASGS) that applies at the time.

Registration of births is compulsory in Australia under relevant state/territory legislation. However, each state/territory Registrar has its own birth registration form. Most data items are collected in all states and territories and therefore statistics at a national level are available for most characteristics. In some cases, different wording of questions asked on the registration form may result in different answers which may affect final figures.

Use of the supporting documentation released with the statistics is important for assessing coherence within the dataset and when comparing the statistics with data from other sources. Changing processes over time and/or across state/territory registries can affect consistency and hence interpretability of statistical output. Explanatory Notes in each issue contain information pertinent to that particular release which may impact on comparison over time.

Data presented in this publication are reported by year of registration (unless otherwise stated) and differ from birth statistics published in Australian Demographic Statistics (cat. no. 3101.0) which are reported on a year/quarter of occurrence basis in final and revised data for use in population estimates.

Birth registrations data are not the only statistical series of births in Australia. The National Perinatal Data Collection (NPDC) is a national collection on pregnancy and childbirth, based on births reported to the Perinatal Data Collection in each state and territory in Australia. Midwives and other health professionals who attend births complete notification forms for each birth using information obtained from mothers and hospital or other records. This information is compiled and published annually by the National Perinatal Statistics Unit (NPSU) of the Australian Institute of Health and Welfare (AIHW) in Australia's Mothers and Babies. As information from these two collections are from different sources, the statistics obtained may vary. The number of births in the Perinatal Data Collection is generally greater, which may reflect that the parent(s) delay or fail to register the birth of a child. For more information, see Appendix: Differences Between Collections.

INTERPRETABILITY

Birth statistics are generally straightforward and easy to interpret. It should be noted, however, that changes in numbers of births over time can be due to two factors: changes in fertility, and changes in the number of women in child-bearing ages. For this reason, births data need to be considered in relation to the size of the relevant population(s) through the use of fertility rates.

Another aspect that may be overlooked is plurality, or the fact that each birth of a multiple birth is counted individually in births data. Confinement statistics remove the effect of plurality and are used when analysing characteristics of the mother or father; for example, for calculating median ages.

Information on fertility rates, as well as data sources, terminology, classifications and other technical aspects associated with the statistics presented in this publication can be found in the Explanatory Notes, Appendices and Glossary.

ACCESSIBILITY

Births data are available in a variety of formats on the ABS website under the 3301.0 product family. The formats are:

• Web contents, which contains publication commentary; and
• data cubes (in Microsoft Excel spreadsheet format).

Further information on births and fertility may be available on request. The ABS observes strict confidentiality protocols as required by the Census and Statistics Act (1905). This may restrict access to data at a very detailed level which is sought by some users.