Juvenile Justice NMDS 2015–16: Quality Statement
Data Quality Statement Attributes
Identifying and definitional attributes
|Metadata item type:||Data Quality Statement|
AIHW Data Quality Statements, Standard 10/03/2017
|Data quality statement summary:|
Summary of Key Issues
The Juvenile Justice National Minimum Data Set (JJ NMDS) contains information on young people in Australia who were supervised by youth justice agencies because they were alleged or proven to have committed an offence. The JJ NMDS is the only national collection of youth justice data.
The Australian Institute of Health and Welfare (AIHW) compiles the JJ NMDS each year using data extracted from the administrative systems of the state and territory departments responsible for youth justice.
There are a number of data quality and coverage limitations specific to each state and territory. In particular:
Overall, the levels of missing data in the JJ NMDS are very low. Only three variables have rates of missing or unknown data greater than 1%.
The youth justice system is the set of processes and practices for dealing with children and young people who have committed or allegedly committed offences. In Australia, youth justice is the responsibility of state and territory governments, and each state and territory has its own youth justice legislation, policies and practices.
The JJ NMDS contains information on all children and young people in Australia who are supervised by youth justice agencies, both in the community and in detention.
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.
The AIHW aims to improve the health and wellbeing of Australians through better health and welfare information and statistics. It collects and reports information on a wide range of topics and issues, ranging from health and welfare expenditure, hospitals, disease and injury and mental health to ageing, homelessness, disability and child protection.
The Institute also plays a role in developing and maintaining national metadata standards. This work contributes to improving the quality and consistency of national health and welfare statistics. The Institute works closely with governments and non-government organisations to achieve greater adherence to those standards in administrative data collections to promote national consistency and comparability of data and reporting.
One of the main functions of the AIHW is to work with the states and territories to improve the quality of administrative data and, where possible, to compile national data sets based on data from each jurisdiction, to analyse the datasets and disseminate information and statistics.
The Australian Institute of Health and Welfare Act, in conjunction with the compliance provisions of the Privacy Act 1988 (Cwth), ensures that the data collections managed by the AIHW are kept securely and under the strictest conditions to preserve privacy and confidentiality.
For further information, see the AIHW website www.aihw.gov.au/.
The data for the JJ NMDS are provided to the AIHW by those state and territory departments responsible for youth justice. These departments include:
The reference period for the 2015–16 JJ NMDS is from 1 July 2000 to 30 June 2016. This means that in 2015–16, data were resupplied for the period 2000–01 to 2014–15, and data for 2015–16 were supplied for the first time. The data set includes young people who were under youth justice supervision at any time during that period.
The state and territory departments responsible for youth justice provide data to the AIHW annually, following the end of each financial year. For the 2015–16 collection, the first iteration of data was due for upload and checking on the AIHW’s data validation system within 3 months of the end of the financial year (by 30 September 2016). Five of six participating jurisdictions supplied data within 3 months of the end of the financial year. Data were finalised on schedule for all participating jurisdictions by December 2016.
The first release of JJ NMDS data for each collection period occurs in the Youth justice in Australia bulletin (previously Juvenile justice in Australia). Subsequent publication of these data may occur in other AIHW bulletins and reports, online content, and other publications external to the AIHW.
Publications containing JJ NMDS data, including the annual Youth justice in Australia bulletin and online appendix tables, are available on the AIHW website http://www.aihw.gov.au/publications/youth-justice/. These reports and tables are available free of charge.
Additional information about youth justice in Australia is available from http://www.aihw.gov.au/youth-justice/.
Requests for unpublished JJ NMDS data can be made by contacting the AIHW on (02) 6244 1000 or via email to [email protected]. A cost recovery charge may apply to requests that that take longer than half-an-hour to compile. Depending on the nature of the request, requests for access to unpublished data may require approval from the AJJA and/or the AIHW Ethics Committee.
General inquiries about AIHW publications can be made to the Communications, Media and Marketing Unit on (02) 6244 1032 or via email to [email protected].
Detailed supporting information on the quality and use of JJ NMDS data is available from the AIHW website at www.aihw.gov.au/youth-justice/data-quality/. Readers are advised to consider supporting information to ensure appropriate interpretation of analyses presented by the AIHW. Supporting information includes footnotes to tables and details of the data items, coverage, quality and the methods used in reporting, such as the calculation of counts, rates and supervision periods.
Metadata for the JJ NMDS are available in METeOR, the AIHW’s online metadata repository. METeOR specifications for the collection can be accessed at /content/index.phtml/itemId/470084.
AIHW youth justice reports are available for purchase in hard copy or for download free of charge from www.aihw.gov.au/publications/youth-justice/.
The JJ NMDS contains information on all children and young people who were supervised by a youth justice agency in Australia during the reference period because they:
In Queensland, youth justice legislation applies to children and young people aged 10–16 when the offence was committed or allegedly committed. In all other states and territories, youth justice legislation applies to young people aged 10–17. Although most young people under youth justice supervision are aged 10–17, some are aged 18 and over.
For each young person recorded in the JJ NMDS, data are collected on sex, date of birth, Indigenous status and date of first supervision.
The JJ NMDS contains information on all supervised legal arrangements and orders that youth justice agencies administer (both community-based and detention orders) and all periods of detention in youth justice detention centres.
Supervised legal arrangements and orders include police-referred detention before the first court appearance; court-referred remand; supervised bail; and sentenced orders, such as community service orders, probation, suspended detention, sentenced detention and parole or supervised release.
Periods of detention include police-referred detention (before the young person’s initial court appearance), remand (court-referred detention following a court appearance) and sentenced detention.
For each period of supervision, data are collected on:
The JJ NMDS does not contain information on children and young people in the youth justice system who were not supervised (for example, young people on unsupervised bail), or who were supervised by other agencies, such as police.
Data published in the Youth justice in Australia bulletins include numbers and rates of young people under supervision both on an average day and during the year, the characteristics of those young people and information on the types of supervision they experienced.
Data for the JJ NMDS are extracted each year from the administrative systems of the state and territory departments responsible for youth justice in Australia, according to definitions and technical specifications agreed to by the departments and the AIHW.
Overall, the levels of missing data in the JJ NMDS are very low. About 7% of all young people in the JJ NMDS since 2000–01 have an unknown Indigenous status, and similar proportions of records in each of the order (7%) and detention (6%) files have unknown or missing information for the postcode and suburb of the young person’s usual residence. For all other variables in the JJ NMDS, the proportion of missing data is 1% or less.
Each year, most jurisdictions supply data from 2000–01 to the most recent financial year, incorporating updates to data as required. Trend data may therefore differ from those published in previous Youth justice in Australia reports due to data revisions. The most recent data are the most accurate.
There are a number of data quality and coverage limitations specific to each state and territory. In particular, the Northern Territory did not provide JJ NMDS data for 2008–09 to 2015–16. In 2015–16, the Northern Territory provided non-standard data for the period 2011–12 to 2015–16. Therefore, many data tables contain two totals:
In addition, some analyses of trends exclude those states and territories with incomplete data in the new format due to comparability issues. Readers are advised to read the supporting information in publications (such as footnotes to tables and details of the methods used to compile the data) to ensure appropriate interpretation.
Data quality issues specific to each state and territory include the following:
New South Wales
In New South Wales, the Kariong Juvenile Justice Centre was transferred from the NSW Department of Juvenile Justice to the NSW Department of Corrective Services on 10 November 2004 and renamed the Kariong Juvenile Correctional Centre. As the JJ NMDS includes only young people who are supervised by youth justice agencies in Australia, information about young people in custody in the Kariong Juvenile Correctional Centre after 10 November 2004 is not included. In 2012–13 there were 28 young people on an average day in the Kariong Juvenile Correctional Centre, and therefore they formed only a small proportion (around 8%) of young people in detention in New South Wales.
Kariong Juvenile Correctional Centre was closed in early 2015. During April and May 2015, 23 young people were transferred out of the Kariong Centre to another youth detention centre under the supervision of Juvenile Justice NSW. All young people under the age of 18 years who were transferred out of the Kariong Centre, and who entered the supervision of Juvenile Justice NSW, entered the JJ NMDS data collection on the date they were transferred.
The 2015-16 reporting period is the first year to include JJ NMDS data from Western Australia since 2007–08. For the 2015–16 collection, the Western Australia data supply included only the sentenced detention period, where a young person was both sentenced and unsentenced at the same time. As a result, there may be an undercount of young people on unsentenced detention orders.
For Tasmania, complete data on detention periods and orders are available only for 2006–07 onwards. Because data on length of detention are used to derive the time spent under community-based supervision, information on periods of community-based supervision before 2006–07 may therefore be incomplete and are not reported.
Australian Capital Territory
For the Australian Capital Territory, data for 2000–01 to 2002–03 are not available and data for 2003–04 to 2007–08 are available only in JJ NMDS 2007 format. Some trend analyses therefore exclude the Australian Capital Territory.
In the Australian Capital Territory, both police-referred pre-court detention and remand (court-referred detention) are recorded as remand.
The end reasons for orders are not available for the Australian Capital Territory.
The Northern Territory did not provide JJ NMDS data for 2008–09 to 2015–16. Limited data in a non-standard format were provided for 2011–12 to 2015–16. These data are included in the analyses where possible.
Data for 2007–08, which are the most recently available JJ NMDS data for the Northern Territory, are used in the national totals for 2008–09 and 2009–10 where possible, but are not reliable enough for separate reporting.
Data for 2000–01 to 2007–08 are available only in JJ NMDS 2007 format. Some trend analyses therefore exclude the Northern Territory.
The JJ NMDS was initially developed between 2002 and 2004, and the first report containing data from the JJ NMDS was published in 2006. This first version of the JJ NMDS (referred to as JJ NMDS 2007 on METeOR) contained information on only the most serious supervised legal arrangement or order for each young person under youth justice supervision (see Juvenile justice in Australia 2007–08 for more information).
In 2009, the JJ NMDS was redeveloped to capture all supervised legal arrangements and orders for young people under youth justice supervision, rather than only the most serious one. This version of the JJ NMDS (known as JJ NMDS 2009) allows for more complete analyses of the numbers and types of supervised orders that youth justice agencies administer. Juvenile justice in Australia 2008–09 was the first report to contain data from the redeveloped JJ NMDS.
For the 2014–15 JJ NMDS collection, the reference period was 2000–01 to 2014–15. Data were resupplied for the period 2000–01 to 2013–14. Trend data may therefore differ from those previously published due to data revisions.
JJ NMDS data from South Australia for 2014–15 may vary from that reported in previous years due to improvements in data quality and assurance.
Data from the JJ NMDS are also report in the annual Report on government services published by the Steering Committee for the Review of Government Service Provision, and were used in the Juveniles in detention in Australia report published by the Australian Institute of Criminology (AIC). The two most recent AIC reports contain data from the JJ NMDS; these data are the number in detention on the last night of each quarter. Earlier reports published by the AIC contain end-of-quarter data supplied directly by the states and territories.
Source and reference attributes
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