AODTS NMDS coverage and data quality

The Alcohol and Other Drug Treatment National Minimum Dataset (AODTS NMDS) includes government publicly funded alcohol and other drug treatment specialist services across Australia, including government and non-government agencies. Data is collected annually.

Although the AODTS NMDS collection covers most publicly funded AOD treatment services, it is difficult to quantify the full scope of AOD services in Australia. In 2013–14 it was estimated that AOD treatment comprised 1.6 million treatment episodes, services or contacts each year. Of these, the AODTS NMDS accounts for an estimated 10% of episodes, and between 20–30% of individual clients who received AOD treatment in Australia (Ritter A et al 2014).

Further details on scope, coverage and data quality are available from the AODTS NMDS Data Quality Statement and via the AIHW’s Metadata Online Registry (METEOR).

Analysis variables and exclusion criteria

Table 4 provides an overview of variables included in this report and their relevant analysis criteria.

Table 4: Summary of analysis criteria
Variable Analysis criteria

Treatment cohort-level data



Clients aged less than 10 years and over aged over 100 excluded

Clients with age missing excluded


Sex listed as ‘other’ and missing excluded

Treatment intensity

Clients were excluded from treatment intensity cohort analysis if they:

  • received their first recorded closed treatment episode between 1 July 2019 and 30 June 2021
  • were referred from another AOD treatment service for their initial episode in the 2013–14 collection period
  • received treatment only for another person’s AOD use

Treatment episode-level data


Reason for cessation

Missing or invalid excluded

Client type

Clients receiving treatment for others’ AOD use excluded

Principal drug of concern

Alcohol and amphetamines included

Main treatment type

Exclude ‘assessment only’

Client remoteness area

Episodes delivered prior to 2013–14 excluded.

Episodes with an invalid postcode excluded.


No exclusions

Delivery setting

No exclusions

Referral source

No exclusions

Reason for cessation variable – capabilities and limitations

In 2011, a review was undertaken to assess the AODTS NMDS as an information source for services policy development, data gaps, and options for future development within the collection.

This review examined the capabilities and limitations of variables included in the NMDS, including reason for cessation. Further details on the capabilities and potential future development of this data element can be viewed at Review of the Alcohol and Other Drug Treatment Services National Minimum Data Set (AIHW 2011).


  • provides a general overview for why clients cease treatment
  • can be generally categorised into expected and unexpected/administrative reasons which have been used as proxies for treatment episode outcome.


  • the number of codes available in the AODTS-NMDS is fewer than those available in some jurisdiction. Consequently, there is some detail lost in the mapping required for national reporting and agencies may feel that they are not accurately reporting their activity
  • differences in agency philosophy or service delivery model may influence how this is coded; for example, favouring the codes for mutually agreed and treatment completed as opposed to involuntary/without notice/against advice
  • the reason for cessation ‘treatment completed’ is problematic because there is no record of the original intention for that episode
  • where episodes are forced closed due to unintended lack of contact with the client for 3 months, the reason of cessation may be inconsistently recorded
  • from stakeholder consultation, there is reason to believe that some agencies record reason for cessation as ‘transfer to another AOD provider’ and a new episode is opened at the same agency, inflating the number of episodes that that agency provides
  • where a client is receiving treatment for more than one drug and these have been coded as separate episodes (principal drugs of concern) the reason for cessation ‘change in the principal drug of concern’ is unlikely to be used. This is also a method of inflating the number of treatment episodes provided by an agency
  • the reason ‘change in the delivery setting’ poses administrative problems, especially for some treatment types such as counselling and outreach case management where contacts may occur in several different locations during a single episode. This characteristic of the collection appears unmanageable for continuum of care models of treatment services
  • some agencies perceive this element as a measure of efficacy and tend to code for ‘treatment completed’ regardless of the actual reason for cessation
  • where the main treatment type is assessment only, there is no information on the result of that assessment

Identifying clients in the AODTS NMDS

Unique clients were identified using a statistical linkage key (SLK-581).

See the AODTS NMDS SLK-581 Guide for use (PDF, 95kB) for further info.

Defining treatment episodes

An episode of treatment for alcohol and other drugs is the period of contact, with defined dates of commencement and cessation, between a client and a treatment provider or team of providers in which there is no change in the main treatment type or the principal drug of concern, and there has not been a non-planned absence of contact for greater than 3 months.

For further information, please refer to Alcohol and other drug treatment services in Australia annual report, Key terminology and glossary.

Client postcode and remoteness

In 2013–14, the data element Postcodeof client was added to the AODTS NMDS episode file to enable geographic analysis of clients. This data item refers to the postal code of the client’s last known home address at the start of the treatment episode.

Postcode data collected in the AODTS NMDS has varied greatly in its quality since its introduction in the 2013–14 collection period. In particular, these variations may affect data quality for clients experiencing circumstances such as having no fixed address.

It is also important to note that postcodes were not developed with geospatial analysis in mind. While there are issues with using postcode for geospatial analysis, postcodes can be converted to various ASGS ABS and non-ABS structures to produce overall fit for purpose geography.

In this report, the Postcode 2018 listing was converted to the ASGS 2016 Remoteness Area Structure, using the ABS Postcode 2018 to Remoteness Area 2016 correspondence file. This correspondence is listed as a ‘good’ conversion, indicating that it is expected to convert data to a high degree of accuracy, and that the converted data will reflect the actual characteristics of the geographic areas involved.

Australian Statistical Geography Standard (ASGS) Remoteness Structure 2016

The ASGS has been developed by the ABS to allow areas that share common characteristics of remoteness (such as relative access to services) to be classified into broad geographic regions of Australia. These areas are:

  1. Major cities
  2. Inner regional
  3. Outer regional
  4. Remote
  5. Very remote

Further information on ASGS geographical correspondences can be viewed on the ABS website.