3301.0 - Births, Australia, 2017 Quality Declaration 
Latest ISSUE Released at 11:30 AM (CANBERRA TIME) 11/12/2018   
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EXPLANATORY NOTES


SCOPE AND COVERAGE

1 Statistics in this release relate to the number of births registered during the calendar year shown, unless otherwise stated. Statistics relating to births by year of occurrence can be obtained from ABS.Stat available from the 'Downloads' tab of this release on the ABS website.


Scope of birth registration statistics

2 The ABS Birth Registrations collection includes all births that occurred and were registered in Australia, including births to mothers whose place of usual residence was overseas.

3 The scope of the statistics includes:

  • all births that were live born and were not previously registered;
  • births that occurred within Australian Territorial waters;
  • births to temporary visitors to Australia;
  • births that occurred in Australian Antarctic Territories and other external territories;
  • births occurred on Norfolk Island from 1 July 2016 are included. This is due to the introduction of the Norfolk Island Legislation Amendment Act 2015. Norfolk Island births are included in statistics for 'Other Territories' as well as totals for all of Australia. Births occurring on Norfolk Island prior to 1 July 2016 were not in scope for birth statistics;
  • births that occurred 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).

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

5 The scope for each reference year of the Birth Registrations collection includes:
  • births registered in the reference year and received by the ABS in the reference year;
  • births registered in the reference year and received by the ABS in the first quarter of the subsequent year; and
  • births registered in the years prior to the reference year but not received by the ABS until the reference year or the first quarter of the subsequent year, provided that these records have not been included in any statistics from earlier periods.

6 Birth records received by the ABS during the March quarter of 2018, which were registered in 2017, were assigned to the 2017 reference year. Any registrations relating to 2017 which were received by the ABS from April 2018 were assigned to the 2018 reference year and will be reported in the next iteration of this publication.

7 Prior to 2007, the scope for the reference year of the Birth Registrations collection included:
  • births registered in the reference year and received by the ABS in the reference year;
  • births registered in the reference year and received by the ABS in the first quarter of the subsequent year; and
  • births registered during the two years prior to the reference year but not received by the ABS until the reference year.


Coverage of birth statistics

8 Ideally, for compiling annual time series, the number of 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 Registries of Births, Deaths and Marriages, data in this release are presented on a year of registration basis.

9 There are three dates attributable to each birth registration:
  • the date of occurrence (of the birth);
  • the date of registration or inclusion on the state/territory register; and
  • the month and year in which the registered birth is provided to the ABS.

10 Data in this release 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:
  • For births registered in New South Wales, Victoria, Western Australia and the Australian Capital Territory, the birth registration date is the date at which the record is entered into the registration processing system.
  • For births registered in Queensland, the registration date is the date at which all data on the birth record are finalised. This may be before the birth is entered into the registration system.
  • For births registered in South Australia, preliminary and final registration dates are allocated. Where a record requires further information a preliminary date is assigned. Once all data are finalised, a final registration date is assigned to the birth record which is provided to the ABS as the registration date.
  • For births registered in Tasmania, a date is allocated when the birth record is entered into the registration system. The ABS receives an 'insertion' date which is the date when any information relating to the birth is entered into the registration system and this is the registration date.
  • For births registered in the Northern Territory, the registration date is the date at which the record is entered into the registration system. For birth records not received by the Registry within 60 days of the birth, the Registry will register the child as 'unnamed' and not finalised.


CLASSIFICATIONS

Nuptiality

11 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:
  • nuptial where the father registered was married to the mother at the time of the child's birth, or where the husband died during the mother's pregnancy (confinements and births to Aboriginal and Torres Strait Islander mothers considered to be tribally married to the father of the child are classified as nuptial); and
  • ex-nuptial where the parents were not in a registered marriage at the time of the child's birth, irrespective of whether the parents were living together at the time of the birth.

12 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).


Geography

13 This issue of Births, Australia includes data cubes containing birth and fertility statistics on the Australian Statistical Geography Standard (ASGS) and the Standard Australian Classification of Countries (SACC).

14 For further information refer to:

DATA SOURCES

15 Registration of births is the responsibility of state and territory Registries 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 Registries for compilation into aggregate statistics in this release. Core data items are collected in all states and territories and therefore statistics at the national level are available for key characteristics. Some states collect additional information.

16 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, parents are contacted by reminder letters and/or phone calls.


State and territory data

17 As a result of an amendment made in 1992 to section 17(a) of the Acts Interpretation Act 1901-1973 (Commonwealth), the Indian Ocean territories of Christmas Island and Cocos (Keeling) Islands have been included as part of geographic Australia since 1993, 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. From 1 July 2016, Other Territories also include Norfolk Island following the introduction of the Norfolk Island Legislation Amendment Act 2015.

18 Prior to 1993, births to mothers usually resident in Christmas Island or Cocos (Keeling) Islands were included with Offshore areas and Migratory in Western Australia, while births to mothers usually resident in Jervis Bay Territory were included with the Australian Capital Territory.

In 2017, there were 30 births to mothers usually resident in Christmas Island, the Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island.

19 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 both a state or territory of registration basis and usual residence 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, Jervis Bay Territory and Norfolk Island) cannot be registered in Other Territories but are registered in other Australian states and territories.


Births, State or territory of usual residence of mother by state or territory of registration - 2017

State or territory of registration (a)
State or territory of usual residence
NSW
Vic.
Qld
SA
WA
Tas.
NT
ACT
Aust.(a)

New South Wales
93 540
1 330
666
35
17
5
4
996
96 591
Victoria
86
81 879
31
60
23
6
1
5
82 094
Queensland
531
82
60 506
7
19
3
11
-
61 158
South Australia
24
36
11
18 952
17
3
30
4
19 072
Western Australia
49
35
21
10
34 350
2
30
-
34 498
Tasmania
8
37
13
1
5
5 545
-
-
5 610
Northern Territory
34
23
50
19
16
-
3 738
4
3 882
Australian Capital Territory
139
8
3
1
-
-
-
6 055
6 207
Other Territories(b)
9
1
6
-
14
-
-
-
30
Australia(b)
94 420
83 431
61 307
19 087
34 461
5 562
3 815
7 059
309 142

- nil or rounded to zero (including null cells)
(a) Small data cells have been randomised to preserve confidentiality. As a result, sums of components may not add exactly to totals. Cells with a value of zero have not been affected by this randomisation. See explanatory note 47 for more information.
(b) Births occurred on Norfolk Island from 1 July 2016 are included. See Explanatory Note 3 for more information.


20 In 2017, there were 334 births registered in Australia to women who usually lived overseas. These have been included in this release with state or territory of usual residence classified according to the state or territory in which the birth was registered.


Births, Mother usually resident overseas

State or territory of registration (a)
2010
2011
2012
2013
2014
2015
2016
2017

New South Wales
316
267
292
274
340
404
362
291
Victoria
13
9
5
8
12
8
12
9
Queensland
15
20
31
25
20
25
25
17
South Australia
2
2
-
-
1
4
1
1
Western Australia
9
8
10
11
17
17
18
11
Tasmania
-
-
-
1
1
-
-
-
Northern Territory
4
1
4
-
-
-
1
-
Australian Capital Territory
3
4
-
-
3
1
1
5
Australia Total (a)
356
308
339
319
394
459
423
334

- nil or rounded to zero (including null cells)
(a) Small data cells have been randomised to preserve confidentiality. As a result, sums of components may not add exactly to totals. Cells with a value of zero have not been affected by this randomisation. See explanatory note 47 for more information.
(b) Includes Other Territories.


Sub-state/territory fertility rates

21 Age-specific and total fertility rates for sub-state/territory regions (for example, Statistical Areas Level 2) presented in this release 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 birth registration data for the reference year only.


DATA QUALITY

Interval between occurrence and registration of births

22 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.


Births registered in 2017, Year of occurrence

2010 and earlier
2011
2012
2013
2014
2015
2016
2017
State or territory of registration
%
%
%
%
%
%
%
%

New South Wales
1.6
0.2
0.4
0.4
0.5
0.9
16.7
79.3
Victoria
0.9
0.2
0.3
0.4
0.4
0.8
15.9
81.3
Queensland
2.0
0.3
0.6
0.6
0.7
1.1
10.4
84.3
South Australia
1.4
-
0.1
0.2
0.3
0.6
9.5
88.0
Western Australia
1.6
0.1
0.2
0.2
0.3
0.5
9.2
88.0
Tasmania
1.4
-
0.1
0.3
0.3
0.2
3.6
94.1
Northern Territory
0.4
-
0.1
-
0.2
0.3
8.0
91.1
Australian Capital Territory
0.1
0.1
0.1
0.1
0.2
0.5
20.8
78.2
Australia
1.4
0.2
0.4
0.4
0.4
0.8
13.7
82.7

- nil or rounded to zero (including null cells)


23 Of the 309,142 births registered in Australia in 2017, 82.7% occurred in 2017, 13.7% occurred in 2016 and the remainder (3.6%) occurred in 2015 or earlier years.


Effects of registration lags on multiple birth statistics

24 In recent years there have been 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 match the number of such confinements registered in that year. For more information on the coverage of a reference year, see paragraph 5.


Registration lags in Queensland

25 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 improvements in the timeliness of registration of births in Queensland.

26 The December quarter of 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. This project is now complete.


Births registered in Queensland, Year of registration by year of occurrence

Year of registration
2010
2011
2012
2013
2014
2015
2016
2017
Year of occurrence
%
%
%
%
%
%
%
%

2007 and earlier
4.1
3.6
2.8
2.0
1.9
1.8
1.6
1.7
2008
0.5
0.2
0.4
0.4
0.2
0.1
0.1
0.1
2009
11.0
0.4
0.3
0.4
0.4
0.2
0.1
0.1
2010
84.4
9.2
0.5
0.3
0.4
0.4
0.3
0.1
2011
-
86.5
8.9
0.5
0.4
0.4
0.5
0.3
2012
-
-
87.2
9.7
0.6
0.4
0.5
0.6
2013
-
-
-
86.7
9.8
0.6
0.5
0.6
2014
-
-
-
-
86.4
10.6
0.9
0.7
2015
-
-
-
-
-
85.3
10.0
1.1
2016
-
-
-
-
-
-
85.6
10.4
2017
-
-
-
-
-
-
-
84.3

- nil or rounded to zero (including null cells)


New South Wales births registrations

27 In June 2014, the New South Wales Registry of Births, Deaths and Marriages (NSW Registry) transitioned to a new data processing system which resulted in temporary processing delays. These delays caused a number of birth records received by the NSW Registry in 2014 to be processed in 2015. As a result, the total number of births registered in New South Wales in 2014 (91,074) was 9,388 (9.3%) less than the number registered in 2013 (100,462).

For a more complete understanding of the births occurring in NSW for 2014 users should consult Table 13 in the .PDF version of Australian Demographic Statistics (3101.0), as well as the dataset Births, by year and month of occurrence, by state (in this publication).

Analysis by the ABS showed that the distribution of important characteristics such as sex of child, age of mother, usual residence of mother and Indigenous status in 2014 data is similar to that in 2011-2013 data.

28 The delayed birth registrations contributed to the increase of 9,005 registrations between 2014 and 2015. There was a greater registration lag, indicated by the high proportion of births registered in New South Wales in 2015 that occurred in 2014. After taking account of the extra lag, a decline in registrations after 2013 is still apparent.

29 In 2016 the NSW Registry changed the 'proof of identity' requirements for parents registering a new birth. This led to delays in registration of births for 2016 and 2017. The ABS has been working with the NSW Registry to improve the birth registration lag. The recent launch of the new online birth registration processes in 2018 by the NSW Registry appears to be improving birth registration time frames for both Aboriginal and Torres Strait Islander and non-Indigenous Australians.


Births registered in New South Wales, Year of registration by year of occurrence

Year of registration
2010
2011
2012
2013
2014
2015
2016
2017
Year of occurrence
%
%
%
%
%
%
%
%

2007 and earlier
3.6
3.3
2.2
1.7
1.2
1.6
1.4
1.4
2008
0.5
0.3
0.2
0.3
0.2
0.1
0.1
0.1
2009
10.8
0.5
0.3
0.3
0.2
0.2
0.1
0.1
2010
85.1
9.0
0.4
0.3
0.3
0.4
0.2
0.1
2011
-
86.9
9.5
0.5
0.2
0.4
0.4
0.2
2012
-
-
87.4
11.6
0.4
0.4
0.4
0.4
2013
-
-
-
85.3
10.0
0.6
0.4
0.4
2014
-
-
-
-
87.5
15.0
0.8
0.5
2015
-
-
-
-
-
81.3
12.9
0.9
2016
-
-
-
-
-
-
83.4
16.7
2017
-
-
-
-
-
-
-
79.3

- nil or rounded to zero (including null cells)


Tasmanian births registrations

30 The Tasmanian Births, Deaths and Marriages Registration Act 1999 requires hospitals, doctors, midwives or other responsible persons to provide the Tasmanian Registry 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.

31 Under the Act, the birth of a child must also be registered by lodging a birth registration statement with the Registry 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 Registry provides the 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.

32 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. Since 2007 these records have been excluded from all nuptiality statistics. Since 2013 the ABS no longer received birth notifications, and therefore there are no more unmatched birth registration forms.


Northern Territory births registrations

33 In early 2018, the Northern Territory Registry of Births, Deaths and Marriages identified a processing issue that had resulted in additional delays to the registration of some births. These births will be processed and included in 2018 counts. Care should therefore be taken when interpreting changes in birth counts and fertility rates for the Northern Territory in recent years.


Births registered in the Northern Territory, Year of registration by year of occurrence

Year of registration
2010
2011
2012
2013
2014
2015
2016
2017
Year of occurrence
%
%
%
%
%
%
%
%

2007 and earlier
0.2
0.4
0.4
0.3
0.3
0.3
0.4
0.3
2008
-
-
-
0.1
-
-
-
-
2009
8.3
0.1
0.1
-
0.2
-
-
0.1
2010
91.5
7.3
0.1
0.1
0.2
-
-
-
2011
-
92.2
6.6
-
0.1
0.1
-
-
2012
-
-
92.7
6.3
0.3
0.1
-
0.1
2013
-
-
-
93.3
6.3
0.2
0.1
0.1
2014
-
-
-
-
92.7
5.2
0.1
0.2
2015
-
-
-
-
-
94.2
5.6
0.3
2016
-
-
-
-
-
-
93.7
8.0
2017
-
-
-
-
-
-
-
91.1

- nil or rounded to zero (including null cells)


Australian Capital Territory births registrations

34 An increase in the processing of late registrations in 2017, compared to earlier years, has contributed to a higher than expected fertility rate for the territory. Care should be taken when interpreting changes in the Australian Capital Territory births when comparing 2017 to earlier years.


Births registered in the Australian Capital Territory, Year of registration by year of occurrence

Year of registration
2010
2011
2012
2013
2014
2015
2016
2017
Year of occurrence
%
%
%
%
%
%
%
%

2007 and earlier
0.9
0.5
0.4
0.2
0.4
0.2
0.3
0.1
2008
0.2
0.1
0.1
0.1
-
0.1
-
-
2009
8.1
0.3
0.2
0.1
-
-
-
-
2010
90.8
7.3
0.2
0.1
0.2
0.1
-
-
2011
-
91.8
9.1
0.2
0.2
0.2
0.1
0.1
2012
-
-
90.0
9.5
0.2
0.1
0.1
0.1
2013
-
-
-
89.7
9.8
0.2
0.1
0.1
2014
-
-
-
-
89.2
11.7
0.3
0.2
2015
-
-
-
-
-
87.4
14.2
0.5
2016
-
-
-
-
-
-
84.9
20.8
2017
-
-
-
-
-
-
-
78.2

- nil or rounded to zero (including null cells)


Aboriginal and Torres Strait Islander births and fertility rates

35 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:
  • Aboriginal and/or Torres Strait Islander mothers, including births where both the mother and father are Aboriginal and/or Torres Strait Islander Australians; or
  • Aboriginal and/or Torres Strait Islander fathers and non-Indigenous mothers.

36 There are several data collection forms on which people are asked to state whether they are an Aboriginal and/or Torres Strait Islander Australian. The results are not always consistent. The likelihood that a person will report, or be recorded, as an Aboriginal and/or Torres Strait Islander Australian on a specific form is known as their propensity to identify.

37 Propensity to identify and be recorded as an Aboriginal and/or Torres Strait Islander Australian is determined by a range of factors, including:
  • how the information is collected (e.g. Census, survey, or administrative data);
  • who completes the form;
  • the perception of why the information is required, and how it will be used;
  • education programs about reporting as an Aboriginal and/or Torres Strait Islander Australian; and
  • cultural aspects and feelings associated with reporting as an Aboriginal and Torres Strait Islander Australian.

38 Data in this release may therefore underestimate the level of Aboriginal and Torres Strait Islander births and the reliability of Aboriginal and Torres Strait Islander 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 in this release, especially with regard to annual change.

Aboriginal and Torres Strait Islander births registered in 2017, Year of occurrence

2010 and earlier
2011
2012
2013
2014
2015
2016
2017
State or territory of registration
%
%
%
%
%
%
%
%

New South Wales
8.6
1.1
1.7
1.7
2.0
3.0
20.4
61.4
Victoria
6.1
1.4
1.7
2.3
2.6
3.2
20.2
62.5
Queensland
10.4
1.3
2.1
2.2
2.7
3.3
14.5
63.5
South Australia
10.0
0.2
0.8
0.8
1.8
2.4
14.0
70.1
Western Australia
14.0
0.7
1.4
1.2
1.5
2.9
15.2
63.1
Tasmania
1.6
-
-
0.7
0.7
0.3
3.6
93.1
Northern Territory
0.7
-
0.2
0.1
0.4
0.8
11.6
86.3
Australia (a)
8.9
1.0
1.6
.1.7
2.0
2.8
16.4
65.6

- nil or rounded to zero (including null cells).
(a) Includes the Australian Capital Territory.


39 From 2006 to 2013, the Indigenous status of the mother and father for births registered in New South Wales was inconsistent with other jurisdictions. Specifically, where one parent was an Aboriginal and/or Torres Strait Islander Australian, the other parent was processed as either 'Aboriginal and Torres Strait Islander' or 'Not stated'. Furthermore, where one parent was 'Non-Indigenous', the other parent was processed as 'Non-Indigenous' or 'Not stated'. The Indigenous status of the child, where the birth was registered in New South Wales, was derived from the Indigenous status of either of the parents. The Indigenous status of births registered in New South Wales from 2006 to 2013 should therefore be interpreted with caution. The New South Wales Registry has since changed their processing rules and registration data since 2014 is consistent with the rest of Australia.

40 The ABS has investigated recent annual variability in the number of births of Aboriginal and Torres Strait Islander peoples. In 2017, 137 births were to mothers who reported themselves as being an Aboriginal and/or Torres Strait Islander Australian (1.0% of children to Aboriginal and/or Torres Strait Islander mothers), and who were born overseas.

Since 2010, these instances have accounted for less than 0.9% of annual births to Aboriginal and/or Torres Strait Islander mothers. Of these births in 2017, 65% were to mothers born in neighbouring countries in the Pacific, such as New Zealand, Samoa and Papua New Guinea, and of these the majority (57 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 9 births to mothers born in Papua New Guinea in 2017 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. However, caution should be exercised when interpreting Aboriginal and Torres Strait Islander data presented in this release.

41 This release 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.

42 The Aboriginal and Torres Strait Islander fertility rates included in this release were calculated using:
43 Estimates of annual numbers of Aboriginal and Torres Strait Islander births in Australia are available from two collections:
  • ABS Birth Registrations: this release is based on the registration of births with the Registry of Births, Deaths and Marriages in each state and territory; and
  • Australian Institute of Health and Welfare (AIHW) National Perinatal Data Collection: these data are primarily about babies born in hospitals and their mothers (see Appendix: Differences Between Collections for more information).

44 Alternatively, it is also possible to derive indirect estimates and projections of numbers of Aboriginal and Torres Strait Islander births, based on 2011 Census-based Aboriginal and Torres Strait Islander population estimates:
  • For 30 June 2001 to 30 June 2010, estimates of the Aboriginal and Torres Strait Islander population were derived from the Aboriginal and Torres Strait Islander resident population as at 30 June 2011 using a reverse survival technique based on Aboriginal and Torres Strait Islander life tables (see Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 2001 to 2026 (cat. no. 3238.0)). Indirect estimates of Aboriginal and Torres Strait Islander births can then be derived using the number of Aboriginal and Torres Strait Islander children aged 0 at 30 June of each year.
  • For 30 June 2012 to 30 June 2026, projections of the Aboriginal and Torres Strait Islander population were derived from the Aboriginal and Torres Strait Islander resident population as at 30 June 2011 using assumptions on future levels of Aboriginal and Torres Strait Islander fertility, mortality and migration. Numbers of projected Aboriginal and Torres Strait Islander births were derived by applying assumed fertility rates to the Aboriginal and Torres Strait Islander female population aged 15-49 years at 30 June of each year (see Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 2001 to 2026 (cat. no. 3238.0)).


Edits and imputations

45 During editing 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 2017, there were 1,980 birth registrations for which place of usual residence was imputed, and 39 registrations for which sex was not reported and was imputed.


Parity (previous children of mother)

46 Australian parity figures are not published in this edition due to parity data being of poor quality for 2014, 2015, 2016 and 2017 registration years.


Age of parent(s)

47 During birth registration processing since 2007, discrepancies were identified between age of mother data and age of mother derived from date of birth of mother as provided to the ABS by the Registries. In 2017, there were 266 records 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 277 records were affected. For years prior to 2007, median age may have been overstated.


RANDOMISED DATA

48 To protect confidentiality, the Australian Bureau of Statistics (ABS) has adopted a technique to randomly adjust cells with small values. Cells with a value of zero have not been affected by this randomisation. As a result, sums of components may not add exactly to totals. The technique has been applied to all data issued in this release with the exception of median age calculations and any sub-state data. These very minor adjustments allow for a greater amount of data to be released, and as they are small, do not affect the utility of the data.


CONFIDENTIALITY

49 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.

50 Where necessary, tables in this release have had small values suppressed or randomised to protect confidentiality. As a result, sums of components may not add exactly to totals. These adjustments allow for a greater amount of detailed data to be released, and, as they are small, do not affect the utility of the data.


ROUNDING

51 Calculations as shown in the commentary sections of this release are based on unrounded figures. Calculations undertaken by data users using rounded figures may differ from those released. Where figures have been rounded in tables, discrepancies may occur between sums of component items and totals.


ACKNOWLEDGEMENTS

52 The ABS' releases draw extensively on information provided freely by individuals, businesses, governments and other organisations. The ABS values the efforts of each state and territory's Registry of Births, Deaths and Marriages to improve the data quality, coverage and timeliness of birth registration information, processes and systems. 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

53 As well as the statistics included in this and related releases, 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.

54 The Australian Institute of Health and Welfare (AIHW) also collects birth data from midwives and other health professionals who attend births. These data are published annually in Australia's Mothers and Babies. Please note there are differences between the ABS and AIHW birth collections; these are discussed in Appendix: Differences Between Collections.