Data and methods


Age is calculated as at the start of the episode.

Data collection process

For most states and territories, the data provided for the national collection are a subset of a more detailed jurisdictional data set used for planning and policy. Figure A1 shows the processes involved in constructing the national data.

Figure A1: Alcohol and other drug treatment data collection flowchart

Drugs of concern

The AODTS NMDS contains data on drugs of concern that are coded using the ABS Australian Standard Classification of Drugs of Concern (ASCDC) (ABS 2011). In this report, these drugs are grouped (Table A1).

Table A1: Groupings of drugs of concern


ASCDC codes

Category Includes


















Other opioids Oxycodone, fentanyl, pethidine



Other analgesics Paracetamol

Sedatives and hypnotics


Alcohol Ethanol, methanol and other alcohols



Benzodiazepines Clonazepam, diazepam and temazepam



Other sedatives and hypnotics Ketamine, nitrous oxide, barbiturates and kava
Stimulants and hallucinogens  3000–3999 Amphetamines Amphetamine, dexamphetamine and methamphetamine
    Ecstasy (MDMA)  
    Other stimulants and hallucinogens Volatile nitrates, ephedra alkaloids, phenethylamines, tryptamines and caffeine




Other Anabolic agents and selected hormones, antidepressants and antipsychotics, volatile solvents, diuretics and opioid antagonists
Not stated 0000–0002 Not stated  

In this report, pharmaceutical drugs were grouped using 10 drug types, making up the pharmaceuticals group for the purposes of the analysis. These drugs correspond to the ASCDC codes and classifications (Table A2).

Table A2: Pharmaceutical drugs of concern, ASCDC codes and classifications

Drug category

ASCDC code

ASCDC classification
(broad group and narrow group/s)
Drug description
(ASCDC base level unit/s)




Organic opiate analgesics





Organic opiate analgesics




Semisynthetic opioid analgesics




Semisynthetic opioid analgesics




Synthetic opioid analgesics



Sedatives and hypnotics

Benzodiazepines n.f.d., alprazolam, clonazepam, diazepam, flunitrazepam, lorazepam, nitrazepam, oxazepam, temazepam, benzodiazepines n.e.c.



Anabolic agents and selected hormones

Anabolic androgenic steroids

Beta2 agonists

Peptide hormones, mimetics and analogues

Other anabolic agents and selected hormones

Not further defined
Anabolic agents and selected hormones n.f.d., anabolic androgenic steroids n.f.d., boldene, dehydroepiandrosterone, fluoxymesterone, mesterolone, methandriol, methenolone, nandrolone, oxandrolone, stanozolol, testosterone, anabolic androgenic steroids n.e.c., beta2 agonists n.f.d., eformoterol, fenoterol, salbutamol, beta2 agonists n.e.c., peptide hormones, mimetics and analogues n.f.d., chorionic gonadotrophin, corticotrophin, erythropoietin, growth hormone, insulin, peptide hormones, mimetics and analogues n.e.c., other anabolic agents and selected hormones n.f.d., sulfonylurea hypoglycaemic agents, tamoxifen, thyroxine, other anabolic agents and selected hormones n.e.c.

Other opioids

1100, 1199, 1200, 1299, 1300–1304, 1306–1399


Organic opiate analgesics

Semisynthetic opioid analgesics

Synthetic opioid analgesics

Not further defined

Organic opiate analgesics n.f.d., organic opiate analgesics n.e.c., semisynthetic opioid analgesics n.f.d., semisynthetic opioid analgesics n.e.c., synthetic opioid analgesics n.f.d., fentanyl, fentanyl analogues, levomethadyl acetate hydrochloride, meperidine analogues, pethidine, tramadol, synthetic opioid analgesics n.e.c.

Other analgesics

0005, 1000, 1400–1499


Non-opioid analgesics

Not further defined
Analgesics n.f.d., non-opioid analgesics n.f.d., acetylsalicylic acid, paracetamol, ibuprofen, non-opioid analgesics n.e.c.

Other sedatives and hypnotics

2000, 2200–2299, 2300–2399, 2500–2599, 2900–2999

Sedatives and hypnotics



Gamma-hydroxybutyrate (GHB) type drugs and analogues

Other sedatives and hypnotics
Sedatives and hypnotics n.f.d., anaesthetics n.f.d., ketamine, nitrous oxide, phencyclidine, propofol, anaesthetics n.e.c., barbiturates n.f.d., amylobarbitone, methylphenobarbitone, phenobarbitone, barbiturates n.e.c., GHB-type drugs and analogues n.f.d., GHB, gamma-butyrolactone, 1,4-butanediol, GHB-type drugs and analogues n.e.c., other sedatives and hypnotics n.f.d., chlormethiazole, kava lactones, zopclone, doxylamine, promethazine, zolpidem, other se

n.f.d—not further defined; n.e.c—not elsewhere classified.

Jurisdictional notes regarding principal drug of concern:

  • South Australia reports a high proportion of treatment episodes where amphetamines are the principal drug of concern due to the SA Police Drug Diversion Initiative (PDDI). In addition, adult cannabis offences are not included in the PDDI due to the SA Cannabis Expiation Notice legislation.
  • Victoria reported a high number of miscellaneous episodes coded as ‘Other drugs’ due to service provider reporting practices and limitations with the reporting system. This system was replaced in 2019–20. In 2019–20 and 2020–21, Victoria continued to report high levels of miscellaneous episodes coded as ‘Other drugs’ or ‘Not stated’ as principal drugs of concern due to service provider reporting practices with the new data reporting system.
  • In Queensland, the proportion of cannabis episodes reported as the principal drug of concern is a result of the police and illicit drug court diversion programs operating in the state.


Duration is calculated in whole days, and only for closed episodes.

Population rates

In this publication, crude rates were calculated using the ABS’s estimated resident population at the midpoint of the data range: that is, rates for 2021–22 data were calculated using the estimated resident population at 31 December 2021. Rates for previous years may differ to previously reported due to updated estimated resident population.

The COVID-19 pandemic and the resulting Australian Government closure of the international border from 20 March 2020, caused significant disruptions to the usual Australian population trends. This report uses Australian Estimated Resident Population (ERP) estimates that reflect these disruptions.

In the year July 2020 to June 2021, the overall population growth was much smaller than the years prior and in particular, there was a relatively large decline in the population of Victoria. ABS reporting indicates these were primarily due to net-negative international migration (National, state and territory population, June 2021 | Australian Bureau of Statistics (

Please be aware that this change in the usual population trends may complicate interpretation of statistics calculated from these ERPs. For example, rates and proportions may be greater than in previous years due to decreases in the denominator (population size) of some sub-populations.

Reason for cessation

The AODTS NMDS contains data on the reason an episode ended (reason for cessation). In this report, these reasons are grouped (Table A3), but data for the individual end reasons are available in the online supplementary tables.

A different method was used for grouping end reasons in reports released before 2014, so trend comparisons across reports should be made with caution. It is possible to compare data at the individual end reasons using the supplementary tables.

Table A3: Grouping of cessation reasons, by indicative outcome type

Outcome type

Reason for cessation

Expected/planned completion

Treatment completed


Ceased to participate at expiation


Ceased to participate by mutual agreement

Ended due to unplanned completion

Ceased to participate against advice


Ceased to participate without notice


Ceased to participate due to non-compliance

Referred to another service/change in treatment mode

Change in main treatment type


Change in delivery setting


Change in principal drug of concern


Transferred to another service provider

Other Drug court or sanctioned by court diversion service
  Imprisoned (other than drug court sanctioned)


Not stated

Remoteness area

This report uses the ABS’s Australian Statistical Geography Standard (ASGS) Remoteness Structure 2016 (ABS 2016b) to analyse the proportion of AOD treatment agencies by remoteness area. This structure allows areas that share common characteristics of remoteness to be classified into broad geographic regions of Australia. These areas are:

  • Major cities
  • Remote
  • Inner regional
  • Very remote
  • Outer regional

The remoteness structure divides each state and territory into several regions based on their relative access to services.

Examples of urban centres in each remoteness area are:

  • Major cities          Canberra, Newcastle
  • Inner regional      Hobart, Bendigo
  • Outer regional     Cairns, Darwin
  • Remote                 Katherine, Mount Isa
  • Very remote          Tennant Creek, Meekatharra.

For this report, the remoteness area of the agency was determined using the Statistical Area Level 2 (SA2) of the agency. Not all SA2 codes fit neatly within a single remoteness category, and a ratio is applied to reapportion each SA2 to the applicable remoteness categories. As a result, it is possible that the number of agencies in a particular remoteness category is not a whole number. After rounding, this can result in there being ‘<0.5%’ agencies in a remoteness area, due to the agency’s SA2 partially crossing into the remoteness area.

The Australian Statistical Geography Standard ASGS has replaced the Australian Standard Geographical Classification 2006 (ABS 2006), which was used in previous reports to calculate remoteness areas. Therefore, remoteness data for 2011–12 and previous years are not comparable with those for 2012–13 and subsequent years.

Service sectors

From 2008–09, agencies funded by the Department of Health under the Non-Government Organisation Treatment Grants Program (NGOTGP) were classified as non‑government agencies. Before this, many of these agencies were classified as government agencies. As a result, trends in service sectors of agencies should be interpreted with caution.

Source of referral: diversion

Throughout Australia, there are programs that divert people who have been apprehended or sentenced for a minor drugs offence from the criminal justice system. Many of these diversions result in clients receiving drug treatment services, who have been referred to treatment agencies as part of a drug diversion program. Since the 1980s, Australian governments have supported programs aimed at diverting from the criminal justice system people who have been apprehended or sentenced with a minor drugs offence.

In Australia, drug diversion program come in two main forms:

  • Police diversion occurs when an offence is first detected by a law enforcement officer. It usually applies for minor use or possession offences, often relating to cannabis, and can involve the offender being cautioned, receiving a fine and/or having to attend education or assessment sessions.
  • Court diversion occurs after a charge is laid. It usually applies for offences where criminal behaviour was related to drug use (for example, burglary or public order offence). Bail-based programs generally involve assessment and treatment, while pre‑ and post-sentence programs (including drug courts) tend to involve intensive treatment and are aimed at repeat offenders.


The number of closed treatment episodes for counselling as a main treatment type has remained the most common treatment type for all clients over all collection years. Fluctuations over time in closed treatment episodes for particular treatment types may be influenced by coding practices, increased funding or changes in treatment policies or capacity to provide specialised alcohol and other drug treatment services, which may contribute to variation in treatment types over time.


Trend data may differ from data published in previous versions of Alcohol and other drug treatment services in Australia, due to data revisions.

Imputation methodology for AOD clients

From the inception of the AODTS NMDS, data have been collected only about treatment episodes provided by AOD treatment services. Data about the clients those episodes relate to have not been available at a national level. An SLK was introduced into the AODTS NMDS for the 2012–13 collection to enable the number of clients receiving treatment to be counted, while continuing to ensure the privacy of these individuals receiving treatment.

An imputation strategy for the collection was developed to correct for the impact of invalid or missing SLKs on the total number of clients. This strategy takes into account several factors relating to the number of episodes per client and makes assumptions relating to spread across agencies. It also takes into consideration the likelihood that an episode with a missing SLK relates to a client that has already been counted through other episodes with a valid SLK.

To ensure an accurate representation of the AODTS client population, imputation was applied to the 2012–13, 2013–14 and 2015–16 AODTS NMDS to account for the proportion of valid SLKs being less than 95% for these years. The national rate of valid SLKs for these years was largely affected by low proportions of valid SLKs in New South Wales.