• AIHW Data Quality Statements, Standard 11/05/2020

• Up until July 2019, States and territories and the Australian Government Department of Social Services (DSS) (‘the jurisdictions’) collected data on the disability support services provided under the National Disability Agreement (NDA).
• The AIHW has compiled the Disability Services National Minimum Data Set (DS NMDS) annually from the information supplied by jurisdictions. The last year of data collected under the DS NMDS related to the 2018–19 financial year.
• Services provided under the NDA have varied by jurisdiction and year.
• The counts of service users have depended on the accuracy of the statistical linkage key. This has varied by jurisdiction and year.
• While every effort has been made to incorporate responses from all service type outlets provided under the NDA, each year a small number have not been included. This varied by jurisdiction and year.
• Some outlets have not reported on all service users, due to administration or other errors, and it is not possible to accurately estimate the number of service users who may be missing from the data as a result. This varied by jurisdiction and year.
• Non-response rates to data items have varied by jurisdiction and year.

The Australian Institute of Health and Welfare (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 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 these 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 datasets based on data from each jurisdiction, to analyse these datasets and disseminate information and statistics.

The Australian Institute of Health and Welfare Act 1987, in conjunction with compliance to the Privacy Act 1988, ensures that the data collections managed by the AIHW are kept securely and under the strictest conditions with respect to privacy and confidentiality.

For further information see the AIHW website www.aihw.gov.au.

The AIHW maintained a minimum data set on disability support services from 1994, firstly as a snapshot collection and then from 2003–04 to 2018–19 as an annual collection. The AIHW received, compiled, edited and verified the DS NMDS data in collaboration with jurisdictions, which retained ownership of the jurisdictional level data and approved any jurisdictional level output before it was released.

DS NMDS data were released annually using data from 2003–04 to 2018–19 (2018–19 was the last year of data collected under the DS NMDS).

The DS NMDS could not be compiled for a given year until each jurisdiction was able to supply and sign-off data for that year. Sign-off of jurisdictional data submissions was due by the December following the end of the collection period. Data have been required to be released by the end of the following June. For the 2018–19 data, the final jurisdiction provided sign-off 28 November 2019.

The AIHW  reported on disability support services collected under the various iterations of the national disability agreements from 1994 to 2020.

The AIHW website provides disability services reports and data which can be downloaded free of charge. Additional disaggregation of data may be requested via a customised data request. The length of time it takes to complete a request depends on several factors and a charge might apply to recover costs.

General enquiries about AIHW publications can be made to the Website and Publishing Unit on (02) 6244 1032 or via email to [email protected].

The main counts of the DS NMDS collection were service users and service type outlets. A service type outlet was a statistical counting unit of an agency that provided a particular NDA service type at, or from, a discrete location. Data were collected, usually by agencies, for each service type outlet.

Data on service users were collected against the service types (service type outlets) over the collection period. Note that service user data were not collected in relation to two of the seven service groups — ‘advocacy, information and alternative forms of communication’ and ‘other support’. Further, the level of information required to be collected varied according to the particular service type. For more information on what information is collected against each service type as well as a description of each service type, see the associated Disability Services NMDS 2018–19 METeOR entry or the DS NMDS data guide.

The scope of services included in the DS NMDS varied in terms of the programs that are provided under the NDA across jurisdictions as well as in what programs were included in the data collection. See ‘Coherence’ for further details.

The National Disability Insurance Scheme (NDIS) was launched in trial sites from 1 July 2013, with progressive roll-out to full scheme from 1 July 2016. As was expected many NDA service users transitioned to the NDIS and hence exited from the DS NMDS collection over that time. This affected data from 2013–14 onwards. Some service type outlets may also have been less responsive because of the complexities associated with the changeover to the NDIS. See ‘Coherence’ for further details.

More information on the DS NMDS is available on the AIHW website. This includes the DS NMDS collection materials.

The DS NMDS collected data on disability support services provided under the NDA. States and territories and the Australian Government collected data from agencies providing these services and supplied it to the AIHW. These data were compiled into the DS NMDS and were released annually. 2020 is the AIHW’s final annual report in this series.

Some service type outlets have had a large number of service users who have minimal contact, such as information and referral services. These service types were required to submit service type outlet information to the DS NMDS but were not required to submit service user or service received information.

See 'accuracy' for further information on coverage.

DS NMDS data is highly relevant for reporting on the use of disability support services provided under the NDA. The data are used for many purposes, including by policy-makers and researchers. The DS NMDS also contains a statistical linkage key for each service user. This enables

researchers to link their database to the DS NMDS (noting that such data linkage can only be done after receiving approvals from various ethics committees).

Metadata information for the DS NMDS are published in METeOR (Disability Services NMDS 2018-19) and in the DS NMDS data guide.

Each year, when all the jurisdictions’ data were compiled into the DS NMDS, a national validation and data linkage process was undertaken.

To form service user counts, a statistical linkage key was used. The statistical linkage key enabled the number of service users to be estimated from data collected from service type outlets and agencies. During any given financial year, a service user could receive services from:

• more than one service type outlet
• more than one agency
• multiple jurisdictions—across state/territory borders, and/or a combination of Australian Government and state/territory services.

In each of these cases, service user counts were estimated by using the statistical linkage key. All counts of the number of service users were dependent on the accuracy of the statistical linkage key. A linkage key was considered to be invalid if any, or all, parts of the key were missing (excluding sex). To link records within the DS NMDS, the statistical linkage key components of each record for a service received were compared electronically with the statistical linkage key components of all other records. Records that had matching statistical linkage keys were assumed to belong to the same individual service user and were linked.

As with all collections that use a statistical linkage key to identify service users, a small degree of mis-identification was expected. That is, because the statistical linkage key was not a unique identifier, there was a small probability that some of the linked records did not belong to the same individual, and, conversely, that some records that did not link did belong to the same individual. Records with missing or invalid statistical linkage keys could not be linked to other records, and were treated as belonging to separate individual service users. This might have resulted in the number of service users being slightly overestimated. In 2018–19, 0.4% of records had an invalid statistical linkage key.

Service type outlet and service user participation rates, as well as the response rates to various data items, were considered when interpreting data. These varied across years and jurisdictions. Data can be considered more reliable as participation and response rates increase.

Jurisdictions reported their service type outlet participation rates—the number of outlets that contributed to the DS NMDS collection compared with the total number of outlets in the jurisdiction. While every effort was made to incorporate responses from all service type outlets provided under the NDA, each year a small number were not included.

Likewise, it was recognised that some outlets did not report on all service users, due to administration or other errors, and it was not possible to accurately estimate the number of service users who might have been missing from the data as a result. All service type outlets were required to estimate the number of service users they helped over the year; however, analysis of these estimates and comparison with jurisdictional reports indicated that such estimations can be of poor quality.

In some instances, non-response rates to data items varied across jurisdictions and years. High levels of non-response reduce the validity and reliability of data, and items with high proportions should be considered with care, especially when comparing data across jurisdictions and collection years. For the DS NMDS, these generally occurred when a service user or service type outlet did not provide/collect information on a service user, or when information could not be derived by statistical linkage processes. In some instances, particular service types were not required to submit data for all measures.

Tabular information on the response rates, participation rates, and the validity and completeness of the statistical linkage key are provided in the supplementary tables to the annual DS NMDS bulletins.

Up until May 2020, DS NMDS data have been collated and published annually by the AIHW, 2018–19 was the last year of data collected under the DS NMDS.

Service type outlet and service user participation rates, as well as the response rates to various data items, have varied across years and jurisdictions (see ‘Accuracy’ for further detail).

The scope of services has also varied across jurisdictions and years in terms of the programs that were provided under the NDA and how they were classified. For example:

• In most jurisdictions, specific mental health services were provided under health, rather than disability, portfolios. However, in Victoria and Queensland, specialist psychiatric disability services were included under the NDA.
• Early intervention services for children with disability fell within the disability support system in some states but are administered under the education portfolio in others.
• From 2012–13, the Northern Territory DS NMDS data included people using Basic Community Care services. Other jurisdictional data did not.
• Residential rehabilitation services within Victoria's psychiatric disability rehabilitation and support sector (PDRSS) were classified by Victoria as non-residential accommodation support services in the DS NMDS, rather than as residential accommodation support services.
• Both the NDIA and the Western Australian Government operated NDIS trials in Western Australia from 1 July 2014 to 30 June 2017. DS NMDS data includes the Western Australian Government-operated NDIS trial sites for those years as these were considered to be services provided under the NDA; whereas service users who moved to the NDIA-operated trial sites were considered to have transitioned to the NDIS from the date at which they had an approved NDIS plan.
  On 1 July 2017, the dual NDIS trial ceased and the Western Australian Government began administering the NDIS in Western Australia. For this reason, as at 30 June 2017, service users of the Western Australian Government-operated trial sites were considered to have transitioned to the NDIS. These service users are flagged in 2016–17 DS NMDS data as having transitioned to the NDIS and are excluded from the 2017–18 data and 2018–19 data.

While there were some changes in the collection over the years, some meaningful comparisons can be made over time, particularly from 2007–08 to 2018–19 (the last year of the collection). Some major changes to the collection over that time include:

• Changes in collection period/method—from 1994 to 2002, data were collected under the Commonwealth State Disability Agreement Minimum Data Set (CSDA MDS) which was run as a ‘snapshot’ collection. Data from the snapshot collections are not strictly comparable to that from the annual data collections (the CSTDA NMDS for 2003–04 to 2008–09 and the DS NMDS from 2009–10 to 2018–19).
• Changes to service type codes:
  • From 1 October 2008, targeted support services (5.04) previously delivered by the Australian Government and included in the service group ‘employment services’ were transferred to state/territory governments and were distributed across various state and territory service type codes.
  • The use of a combined open and supported employment service code (5.03) was discontinued on 1 December 2004.
  • Changes to linkage processes to estimate service user counts occurred in 2007–08. For more information, see Chapter 1 in Disability support services 2008–09.

The NDIS was launched in trial sites from 1 July 2013, with progressive roll-out to full scheme commencing from 1 July 2016. As was expected many NDA service users transitioned to the NDIS and hence exited from the DS NMDS collection over time. This affected data from 2013–14 to 2018–19, and, as jurisdictions reached full roll-out of the NDIS, data provision to the DS NMDS ceased. In particular:

• The Australian Capital Territory Government did not collect DS NMDS data in 2015–16 and 2016–17, and was not required to collect data from 2017–18 onwards (as transition to the NDIS in this jurisdiction was completed by the end of 2016–17).
• New South Wales completed transition to the NDIS during 2017–18, with only 2 quarters of DS NMDS data collected. Existing NSW clients were prioritised and transitioned to the NDIS according to the most intensive disability service type they could access. This meant the majority of clients remaining beyond the 2nd quarter of 2017–18 were those people with lower intensity support requirements in community care and community support, which were mostly provided by small, local providers. After examining data for the first half of 2017–18 and comparing it to that of previous years, NSW concluded that while the data submitted for 2017–18 may be a slight under-enumeration, it was largely representative of what a full year submission would have been.
• The South Australian Government did not collect DS NMDS data in 2018–19 as most clients had transitioned to the NDIS.
• NDIS implementation led to a reduction in the number of service type outlets reporting to the DS NMDS in the Northern Territory in 2018–19. 

See associated DS NMDS bulletins for more information.

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