Australian Government: Australian Institute of Health and Welfare METeOR Home Page

Juvenile Justice National Minimum Data Set Data Quality Statement

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term515023
Registration status:Help on this termAIHW Data Quality Statements, Endorsed 30/04/2013

Data quality

Quality statement summary:Help on this term

Summary of Key Issues

  • The Juvenile Justice National Minimum Data Set (JJ NMDS) contains information on young people in Australia who were supervised by juvenile justice agencies because they were alleged or proven to have committed an offence. The JJ NMDS is the only national collection of juvenile 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 juvenile justice.
  • There are a number of data quality and coverage limitations specific to each state and territory. In particular:
    • Western Australia and the Northern Territory did not provide JJ NMDS data for 2008–09 to 2011–12. Where possible, estimates for Western Australia and the Northern Territory are used to calculate estimated national totals.
    • Data for South Australia for 2011–12 should be interpreted with caution due to the implementation of a new client and case management system.
    • In Tasmania, data are available from 2006–07 onwards only.
    • In the Australian Capital Territory, data prior to 2003–04 are not available, and data for 2003–04 to 2007–08 are only available in JJ NMDS 2007 format.
    • In New South Wales, data on young people in the Kariong Juvenile Correctional Centre after 10 November 2004 are not included.
  • Overall, the coverage of data in the JJ NMDS is very good. Only three variables have rates of missing or unknown data greater than 1%.

Description

The juvenile 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, juvenile justice is the responsibility of state and territory governments, and each state and territory has its own juvenile justice legislation, policies and practices.

The JJ NMDS contains information on all children and young people in Australia who are supervised by juvenile justice agencies, both in the community and in detention.

Each year, the state and territory government departments responsible for juvenile justice supply data to the AIHW under a memorandum of understanding between the Australasian Juvenile Justice Administrators (AJJA) and the AIHW. Those data are compiled into the JJ NMDS, which is the only national collection of juvenile justice data in Australia.

Institutional environment:Help on this term

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 statutory authority established in 1987, governed by a management board and accountable to the Australian Parliament through the Health and Ageing 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/>.

Timeliness:Help on this term

The reference period for the 2011–12 JJ NMDS is from 1 July 2000 to 30 June 2012. This means that in 2011–12, data were resupplied for the period 2000–01 to 2010–11, and data for 2011–12 were supplied for the first time. The data set includes young people who were under juvenile justice supervision at any time during that period.

The state and territory departments responsible for juvenile justice provide data to the AIHW annually, following the end of each financial year. For the 2011–12 collection, the first iteration of data was due to the AIHW within 3 months of the end of the financial year (by 30 September 2012). Three of six jurisdictions supplied data within 3 months of the end of the financial year, and all participating jurisdictions supplied within 4 months. Data were finalised on schedule for all participating justisdictions by January 2013.

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, and other publications external to the AIHW.

For the first time, data from the 2011–12 JJ NMDS are expected to be published in April of the year following the reference period (10 months after the end of the reference period). In previous years, data were expected to be published in August (14 months after the end of the reference period).

 

Accessibility:Help on this term

Publications containing JJ NMDS data, including the annual Youth justice in Australia bulletin and online appendix tables, are available on the AIHW website <www.aihw.gov.au/juvenile-justice-publications/>. These reports and tables are available free of charge.

Additional information about youth justice in Australia is available from <http://www.aihw.gov.au/juvenile-justice/>.

Requests for unpublished JJ NMDS data can be made by contacting the AIHW on (02) 6244 1000 or via email to info@aihw.gov.au. 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 info@aihw.gov.au.

 

Interpretability:Help on this term

Detailed supporting information on the quality and use of JJ NMDS data is available from the AIHW website at <www.aihw.gov.au/juvenile-justice/>.  AIHW youth justice reports are available for purchase in hard copy or for download free of charge from <www.aihw.gov.au/juvenile-justice-publications/>.  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 is available in METeOR, the AIHW’s online metadata repository. METeOR specifications for the collection can be accessed at <http://meteor.aihw.gov.au/content/index.phtml/itemId/378088>.

 

Relevance:Help on this term

The JJ NMDS contains information on all children and young people who were supervised by a juvenile justice agency in Australia during the reference period because they:

  • committed or allegedly committed an offence between the ages of 10 and 17, or
  •  committed or allegedly committed an offence when aged over 17 and were treated as a young person due to their vulnerability or immaturity.

In Queensland, juvenile 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, juvenile justice legislation applies to young people aged 10–17. Although most young people under juvenile 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 juvenile justice agencies administer (both community-based and detention orders) and all periods of detention in juvenile 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:

  • order or detention type
  • start date of the order or detention period
  • end date of the order or detention period
  • reason the order or detention period ended, including whether the order was successfully completed or breached and whether the young person was released from detention on bail or parole
  • suburb and postcode of the young person’s last known home address.

The JJ NMDS does not contain information on children and young people in the juvenile 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.

 

Accuracy:Help on this term

Data for the JJ NMDS are extracted each year from the administrative systems of the state and territory departments responsible for juvenile justice in Australia, according to definitions and technical specifications agreed to by the departments and the AIHW.

Overall, the coverage of data in the JJ NMDS are very good. 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 (6%) and detention (7%) 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, Western Australia and the Northern Territory did not provide JJ NMDS data for the years 2008–09 to 2011–12, and some states and territories did not provide data in the current format for all years of the JJ NMDS (2000–01 to 2011–12). As a result, two types of national totals are calculated for publications where possible—totals based on JJ NMDS data only (excluding Western Australia and the Northern Territory), and estimated national totals (rounded to the nearest five young people) that include all states and territories.

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. There are typically 18–28 young people on an average day in the Kariong Juvenile Correctional Centre, and therefore they form only a small proportion (around 5%) of young people in detention in New South Wales.

Western Australia

Western Australia did not provide JJ NMDS data for 2008–09 to 2011–12. For these years, it provided only limited data in a non-standard format. These data include the number under community-based supervision and in detention at the end of each month, and additional data on community-based orders and detention placements. These data contribute to the national totals where possible, but are not reliable enough for separate reporting.

Data for Western Australia for 2000–01 to 2007–08 are available only in the JJ NMDS 2007 format. Some trend analyses therefore exclude Western Australia. These data were extracted from separate detention and community-based supervision databases and linked using a statistical linkage key. While this linkage is sufficiently accurate for statistical purposes, it is not accurate for administrative purposes such as case management.

South Australia

Data from South Australia for 2011–12 should be interpreted with caution. Implementation of the Connected Client and Case Management System (C3MS) to training centres was undertaken during 2011–12, which may impact on the quality of data provided for the JJ NMDS. South Australia is undertaking processes to validate data.

Tasmania

For Tasmania, complete data on detention periods and orders are available only for 2006–07 onwards. Because data on length of detention is 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.

Northern Territory

The Northern Territory did not provide JJ NMDS data for 2008–09 to 2011–12. Data for 2000–01 to 2007–08 are available only in JJ NMDS 2007 format. Some trend analyses therefore exclude the Northern Territory.

Data for 2007–08, which are the most recently available JJ NMDS data for the Northern Territory, are used in the national totals where possible, but are not reliable enough for separate reporting.

 

Coherence:Help on this term

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 juvenile 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 juvenile 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 juvenile justice agencies administer. Juvenile justice in Australia 2008–09 was the first report to contain data from the redeveloped JJ NMDS.

For the 2011–12 JJ NMDS collection, the reference period was 2000–01 to 2011–12. Data were resupplied for the period 2000–01 to 2010–11. Trend data may therefore differ from those previously published due to data revisions.

The JJ NMDS is also used to compile the AIHW’s Youth detention population in Australia report (previously Juvenile detention population in Australia), which is supplemented with additional data on the number of young people in detention at midnight at the end of each month in the most recently completed financial year. The report, Juvenile detention population in Australia 2012, contains JJ NMDS data up to and including 30 June 2011, supplemented with additional data for the period from July 2011 to June 2012.

These data differ from those published in the annual Juvenile justice in Australia reports in several ways. First, Juvenile detention population in Australia presents the average nightly population for each quarter, while Juvenile justice in Australia presents the average daily population and total population for each year. Second, young people who are concurrently unsentenced and sentenced are classified as sentenced in Juvenile detention population in Australia, but are counted as both sentenced and unsentenced (or once in the total population) in Juvenile justice in Australia. These differences ensure comparability between the JJ NMDS data and the end-of-month data, which are counts of the numbers of young people at midnight and do not distinguish those who are serving a sentence from those who are concurrently sentenced and unsentenced. For the years before July 2008, JJ NMDS 2009 data were used for all states and territories other than Western Australia, the Northern Territory and the Australian Capital Territory, for which JJ NMDS 2007 data were used. In addition, only end-of-month data were used for Western Australia and the Northern Territory for July 2008 onwards.

Data from the JJ NMDS are also reported 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 reports 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.

 

Data products

Implementation start date:Help on this term10/08/2012

Source and reference attributes

Submitting organisation:Help on this termAIHW
My items Help on this term
Download Help on this term