Overview of analysis variables and inclusion criteria

This section provides an outline of the analysis variables and their inclusion criteria for this report.

What is reason for cessation of specialist AOD treatment?

Reasons for cessation can be grouped broadly into 4 categories, outlined below in Table 2.

Treatment episodes without a valid reason for cessation were excluded from analysis.

Table 2: Reasons for cessation recorded in the AODTS NMDS

Expected/planned completion

Ended due to unplanned completion

Referred to another service/ change in treatment mode


  • Treatment was completed as planned
  • Client ceased to participate at expiation or by mutual agreement
  • Ceased to participate against advice
  • Ceased without notice
  • Ceased due to non-compliance


  • Change in main treatment type, delivery setting or principal drug of concern
  • Client was transferred to another service provider


  • Client returned to court or jail due to non-compliance with a drug court program or sanctioned by court diversion service
  • Imprisoned (other than drug court sanctioned)
  • Died
  • Reasons not elsewhere classified

Whose AOD use is examined?

The AODTS NMDS captures whether a treatment episode was provided for a client’s own AOD use or another person’s AOD use.

Treatment episodes where a client received treatment for another person’s AOD use were excluded from analysis.

How is client age and sex defined?

Client age and sex is derived from the first treatment episode a client received when they began treatment between 2013–14 to 2020–21. Clients are identified using a statistical linkage key (SLK-581).

Note that most clients receive multiple treatment episodes, and that their treatment may span several years.

The AODTS NMDS records sex information as ‘male,’ ‘female,’ or ‘other.’ Due to concerns about data reliability, clients whose sex was recorded as ‘other’ are excluded from analysis.

The AODTS NMDS only captures clients aged 10 and older at the time of their first treatment episode.

What treatment episode characteristics are included?

Which drugs of concern are included?

The principal drug of concern is the main substance that the client stated as leading them to seek treatment from the AOD treatment agency. In this report, only clients seeking treatment for their own substance use are included in analyses of principal drug of concern.

In 2020–21, the most common principal drug of concern was alcohol (37% of episodes), followed by amphetamines (24%) (AIHW 2022). Since the beginning of the AODTS NMDS collection, these two drugs have consistently been the most common principal drugs of concern for which clients seek treatment, and are identified as priority substances by the National Drug Strategy 2017–2026.

Analysis of this report was limited to alcohol and amphetamines (an aggregation of methamphetamine, amphetamine and other amphetamines; for further information, refer to the Alcohol and other drug treatment services in Australia annual report).

What treatment types are included?

Treatment type refers to the type of activity used to treat the client’s AOD issues. Each treatment episode has one main treatment type, which is the principal activity identified by the treatment provider to address the client’s issues with their principal drug of concern. For further information on how main treatment type is collected, refer to the Alcohol and drug treatment services in Australia annual report.

Treatment episodes with a main treatment type of ‘Assessment only’ were excluded from analysis. In these episodes, no treatment is provided to the client. Instead, an overall assessment of the extent and nature of their drug and/or alcohol problem is undertaken to assist the patient and clinician to identify shared treatment goals and develop a treatment plan.

How is client remoteness determined?

This report uses the Australian Bureau of Statistics’ (ABS) Australian Statistical Geography Standard (ASGS) Remoteness Structure 2016 to examine the distribution of clients receiving AOD treatment by remoteness area (ABS 2018).

For this report, remoteness area of clients was determined by converting the postcode of the clients’ last recorded address to the ASGS Remoteness Structure. Due to small counts, data for Remote and Very remote regions were aggregated.

Client location is derived from postcode of the client’s last known address, which was collected for the first time in 2013–14. As such, data for episodes provided before 2013–14 are excluded from remoteness analysis. Treatment episodes where the client’s last recorded address had an invalid residential postcode were also excluded, including postcodes assigned to PO boxes.

For further information on client postcode, refer to the Technical notes.

Other variables

Other variables included for analysis include treatment delivery setting, treatment duration and referral source. For further information on these variables, refer to the Data and Methods and Key Terminology and Glossary pages of the Alcohol and other drug treatment services in Australia annual report.