Data source and key concepts

National Community Mental Health Care Database

State and territory health authorities collect a core set of information for the Community Mental Health Care National Minimum Data Set (CMHC NMDS), which is compiled annually into the National Community Mental Health Care Database (NCMHCD). The statistical counting unit used in the NCMHCD is a service contact between either a patient or a third party and a specialised community mental health care (CMHC) service provider.

Data quality over time

Differences in jurisdictional data reporting systems, reduced data coverage or under-reporting of service contacts may contribute to variation in service contact rates. Staff industrial action has resulted in a substantial reduction in data coverage for 2 jurisdictions in some years: Victoria (2011–12, 2012–13, 2015–16 and 2016–17) and Tasmania (2011–12, 2012–13 and 2018–19). New South Wales and the Northern Territory also reported reduced data coverage for 2016–17, 2017–18 and 2018–19. The observed reductions in both service contact and patient numbers are considered to be primarily due to these missing data. Consequently, long term trends in the total number of service contacts are not available. Further information on data coverage can be found in the CMHC NMDS Data Quality Statement.

Data Quality Statements for National Minimum Data Sets (NMDSs) are published annually in AIHW’s Metadata Online Registry (METeOR). These statements provide information on the environment, timelines, accessibility, interpretability, relevance, accuracy and coherence of the Institution. Visit the Community mental health care NMDS 2019–20: National Community Care Database, 2021 Quality Statement. Data quality statements for previous years are also accessible in METeOR.

The footnotes in each of the accompanying MS Excel tables contain details about the calculation of national rates over time.

Patient count

The number of unique patients provided with service contacts can be derived from the NCMHCD. However, the patient count is limited to people registered with state and territory community mental health care systems that have a unique person identifier; a person has one identifier across all individual service providers within a state or territory. The ability of jurisdictions to generate unique person identifiers varies as described in the data quality statement for the CMHC NMDS. 

Community mental health care services key concepts

Key concept Description
Community mental health care Community mental health care refers to government‑funded and operated specialised mental health care provided by community mental health care services and hospital‑based ambulatory care services, such as outpatient and day clinics. 
Length of treatment period


Length of treatment period is the total amount of time between the first and last service contact for each registered patient during the reporting period. Treatment periods are defined in this report as Very brief (1-14 days), Short term (15–91 days) and Medium to longer term (92+ days).
The state and territory mental health acts and regulations provide legislation that safeguards the rights and governs the treatment of patients with mental illness in admitted patient care, residential care and community-based services. The legislation varies between state and territory jurisdictions but all legislation contains provisions for the assessment, admission and treatment of patients on an involuntary basis, defined as ”persons who are detained in hospital or compulsorily treated in the community under mental health legislation for the purpose of assessment or provision of appropriate treatment or care”.
Principal diagnosis The principal diagnosis reported for patients who have a community mental health care service contact is based on the broad categories listed in the Mental and behavioural disorders chapter (Chapter 5) of the International Statistical Classification of Diseases and Related Health Problems, 10th revision, Australian Modification (ICD-10-AM 11th edition). The data quality statement for the CMHC NMDS has further information on principal diagnosis data quality issues.
Service contacts Service contacts are defined as the provision of a clinically significant service by a specialised mental health service provider for patients/clients, other than those admitted to psychiatric hospitals or designated psychiatric units in acute care hospitals and residents in 24‑hour staffed specialised residential mental health services, where the nature of the service would normally warrant a dated entry in the clinical record of the patient/client in question. Any patient can have one or more service contacts over the relevant financial year period. Service contacts are not restricted to face‑to‑face communication and can include telephone, video link or other forms of direct communication. Service contacts can also be either with the patient or with a third party, such as a carer or family member, other professional or mental health worker, or other service provider.
Target population

Some specialised mental health services data are categorised using 5 target population groups (see METeOR identifier 682403):

  1. Child and adolescent services focus on those aged under 18 years.
  2. Older person services focus on those aged 65 years and over.
  3. Forensic health services provide services primarily for people whose health condition has led them to commit, or be suspected of, a criminal offence or will be likely to reoffend without adequate treatment or containment.
  4. General services targets services to the adult population, aged 18 to 64, however, these services may also provide assistance to children, adolescents or older people.
  5. Youth services target children and young people generally aged 16–24 years.

Note that in some states specialised mental health care beds for aged persons are jointly funded by the Australian federal and state and territory governments. However, not all states or territories report such jointly funded beds through the National Mental Health Establishments Database.

Treatment day

Treatment day refers to any day on which one or more service contacts (direct or indirect) are recorded for a registered patient (identified by a patient identifier number assigned to a uniquely identified person) during an ambulatory care episode.

The number of treatment days are grouped as follows in Table CMHC.25: 1–14 days, 15–91 days and 92+ days.