• AIHW Data Quality Statements, Standard 10/08/2012

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.
• 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 2010–11, and some states and territories did not provide data in the current format for all years of the JJ NMDS (2000–01 to 2010–11). Where possible, estimates for Western Australia and the Northern Territory are used to calculate estimated national totals.
• 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.
• Overall, the quality and coverage of data in the JJ NMDS are very good. Only three variables have rates of missing or unknown data greater than 0.1%.

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.

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 <http://www.aihw.gov.au/>.

The reference period for the 2010–11 JJ NMDS is from 1 July 2000 to 30 June 2011. 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 2010–11 collection, the first iteration of data was due to the AIHW within 3 months of the end of the financial year (by 30 September 2011), and data were finalised for all states and territories in January 2012.

The first release of JJ NMDS data for each collection period occurs in the Juvenile justice in Australia report. Subsequent publication of these data may occur in other AIHW bulletins and reports, and other publications external to the AIHW.

Data from the JJ NMDS are expected to be published in August of the year following the reference period (14 months after the end of the reference period). Juvenile justice in Australia 2010–11 was released in August 2012.

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

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 published in Juvenile justice in Australia 2010–11. This report is available in hard copy or free of charge on the AIHW website <www.aihw.gov.au/juvenile-justice/>. 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 </content/index.phtml/itemId/181162>.

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 Juvenile justice in Australia reports include numbers and rates of young people under supervision in 2010–11 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 juvenile justice in Australia, according to definitions and technical specifications agreed to by the departments and the AIHW.

Overall, the quality and coverage of data in the JJ NMDS are very good. Less than 7% of all young people in the JJ NMDS since 2000–01 have an unknown Indigenous status, and around 5% of records in each of the order and detention files have unknown or missing information for the postcode and suburb of the young person’s usual residence. Information on usual address is used to examine the remoteness of usual residence (not available for around 8% of young people under supervision on an average day) and socioeconomic status (not available for around 7%). For all other variables in the JJ NMDS, the proportion of missing data is 0.1% 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 Juvenile justice in Australia reports due to data revisions. The most recent publication reports on the most accurate data.

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 2010–11, and some states and territories did not provide data in the current format for all years of the JJ NMDS (2000–01 to 2010–11). 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.

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 2010–11 JJ NMDS collection, the reference period was 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 Juvenile detention population in Australia report, 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 first report, Juvenile detention population in Australia 2011, contains JJ NMDS data up to and including 30 June 2010, supplemented with additional data for the period from July 2010 to June 2011.

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.