Data sources
The information in this report is based on several data sources.
Department of Defence personnel system data
The Department of Defence compiled a file of current and historical personnel systems for ADF members who have served since 1 January 1985. This combines Personnel Management Key Solution (PMKeyS), Core HR system, D1, CENRESPAY (for reservists), ADFPAY (for permanent members) and other historical payment systems. The Department of Defence and AIHW assessed the resulting file for completeness and duplicates. Comparisons were made with records from Defence annual reports and other sources to validate the list. For ex-serving ADF members, service characteristics are reported as at date of separation from the ADF.
Department of Veterans Affairs (DVA) client data
The DVA client data was used to identify ex-serving ADF members who were eligible for financial and/or healthcare support, from 1 July 2010 to 30 June 2020. There have been significant changes to DVA policy over the study period, particularly in increasing access to non-liability mental health care. Since July 2017, all current and former ADF members have been entitled to non-liability health care for all mental health conditions and are considered DVA clients from first use of these services. While the proportion of DVA clients and the number of services provided by DVA increases - this does not necessarily indicate an increase in the prevalence of mental health conditions.
DVA National Treatment Account (NTA)
The NTA is an administrative data set containing records of DVA-funded health services provided to eligible DVA clients. This includes data for admitted patient care provided in public and private hospitals and for non-admitted emergency department care from 1 July 2010 to 30 June 2020. Data for DVA-funded admitted patient care provided by public hospitals contributed to the Australian suicide and ex-serving ADF member linked datasets
National Mortality Database (NMD)
Cause of Death Unit Record File data are provided to the AIHW by the Australian Coordinating Registry as compiled by the ABS on behalf of Registrars of Births, Deaths, and Marriages (RBDM). Cause of death and demographic items are coded by the Australian Bureau of Statistics (ABS) from data originating from the Registrars of Births, Deaths and Marriages and the National Coronial Information System (managed by the Victorian Department of Justice and Community Safety). The data are maintained by the AIHW in the NMD.
National Death Index (NDI)
The NDI is managed by the AIHW and contains person-level records of all deaths in Australia since 1980 obtained from the Registrars of Births, Deaths and Marriage in each state and territory. NDI use is confined to data linkage studies approved by the AIHW Ethics Committee for health and medical research. NDI records are supplemented with cause of death information from the National Mortality Database (AIHW).
The data quality statement underpinning the NDI can be found at: National Death Index (NDI), Data Quality Statement.
National Hospital Morbidity Database (NHMD)
The National Hospital Morbidity Database (NHMD) is a compilation of episode-level records from the admitted patient morbidity data collection systems in Australian hospitals. It is a comprehensive data set that has records for all episodes of admitted patient care from essentially all public and private hospitals in Australia. The data supplied are based on the National Minimum Data Set (NMDS) for Admitted Patient Care and include administrative, demographic, length of stay and clinical data including diagnoses, procedures and external causes of injury or poisoning. States and territories are primarily responsible for the quality of data. However, the AIHW undertakes extensive validation procedures on receipt of the data, checking for valid values, and logical and historical consistency. Potential errors are queried with jurisdictions.
Key definitions
- An admitted patient undergoes a hospital’s formal admission process to receive treatment and/or care. This may be provided as a day-only or overnight admission. There is variation across jurisdictions as to what requires a day-only or overnight admission. Day-only admissions are generally for treatment or care of at least 4 hours’ duration i.e., brief outpatient clinic appointments for consultation, review or testing are not captured in this data.
- Separation is the term used to refer to an episode of admitted patient care, which can be a total hospital stay, or a portion of a hospital stay when there is a change in care type e.g. from acute care to rehabilitation care. Most episodes represent a single hospital stay. Separation (rather than admission)/number of separations is used as the unit of measurement for episode-based analysis. ‘Separation’ also refers to the completion of an epsiode of care i.e. changing care type, transferring to another hospital, discharge or death. Care type defines the overall nature of the clinical service. There are several care types – acute and mental health care will be the focus of this analysis. Note that mental health care was introduced on 1 July 2015 – prior to this date admitted mental health care was primarily captured within the acute care type, but also rehabilitation, geriatric and psychogeriatric care types.
- Stay refers to the contiguous period of admitted patient care. Most stays are a single separation or episode of admitted patient care. Stays with multiple separations are those with transfers between hospitals, changes in care type e.g. from acute care to rehabilitation care or a day-only transfer for treatment e.g. for a surgical procedure.
- The principal diagnosis is the diagnosis established after study to be chiefly responsible for occasioning the patient’s episode of admitted patient care.
- An additional or secondary diagnosis is a condition or complaint that either coexists with the principal diagnosis, or arises during the episode of care. Generally (diabetes is a notable exception), a secondary diagnosis should only be recorded if the condition affects patient management for that episode of care i.e. it cannot be assumed that the patient does not have a particular condition if it is not recorded.
- External cause/place of external cause ICD-10-AM codes describe the external event, circumstance or condition as the cause or place of injury, poisoning or other adverse effect.
- A separation is referred to as mental health related if a mental health-related principal diagnosis was recorded as either a diagnosis from ICD-10-AM Chapter 5 Mental and behavioural disorders, or a selected diagnosis from other ICD-10-AM chapters or it included any specialised psychiatric care.
- Specialised psychiatric care is provided in a dedicated psychiatric ward or unit. Noting that mental health care is also provided by mental health professionals i.e. psychiatrists, psychologists, nurses, social workers and drug and alcohol counsellors in general wards, outpatient areas and emergency departments. Not all hospitals have specialised psychiatric units to accommodate patients receiving mental health care. Patients who have been admitted involuntarily for treatment of severe mental illness e.g. psychosis or suicidality are generally, if possible, transferred to a hospital with a specialised psychiatric facility by ambulance and/or police.
Information about the NHMD is available on the AIHW website.
The admitted patient care data was available for all states and territories except for Western Australia and the Northern Territory.
National Non-Admitted Patient Emergency Department Care Database
The National Non-Admitted Patient Emergency Department Care Database (NNAPEDCD) is a compilation of episode-level records for non-admitted patients registered for care in emergency departments in selected public hospitals. It provides information on care, including waiting times, in public hospital EDs with designated assessment, treatment, and resuscitation areas, 24/7 medical and nursing staff, and a designated emergency nursing unit manager. The data quality statement and detailed data specifications for the National Non-admitted Patient Emergency Department Care Database (NNAPEDCD) is available online at Hospitals – About the data and About our data- National hospitals data collection.
The ED data was available for all states and territories except for Western Australia and the Northern Territory.
National Health Data Hub
The National Health Data Hub (NHDH) formerly known as the National Integrated Health Services Information Analysis Asset (NIHSI) is an enduring linked data asset managed under the custodianship of the AIHW. This analysis was based on an older version of the asset which had data up to June 2020. The asset includes state/territory hospitals data and national health administrative data sets.
The hospital data includes:
- admitted patient care services public hospitals data for all states and territories except WA and NT
- private hospitals data for QLD, ACT and Victoria
- emergency department services public hospitals data for all states and territories except WA and NT
The national health administrative data includes:
- Medicare Benefits Schedule (MBS) data
- Pharmaceutical Benefits Scheme (PBS) and Repatriation Pharmaceutical Benefits Scheme (RPBS) data
- Residential Aged Care Services data
- National Death Index (NDI).
More information is available at National Integrated Health Service Information (NIHSI) version 2.0 (aihw.gov.au)
The Australian population comparator analysis of admitted patient care and ED used the data held in the asset.
Limitations of the NHMD available in NHDH for this analysis
Private hospital data was not sufficient to analyse admitted patient care services across all Australian states and territories. The version of the NHMD included in NHDH available at the time of analysis included admitted patient care in all public hospitals for participating states and territories (excluding WA and NT) and select private hospital data with limited coverage for Victoria and ACT and complete coverage for Queensland.
Admitted patient care for mental health conditions is provided by both public and private hospitals across Australia. Overall, half of all episodes of admitted patient care for mental health-related care are provided by private hospitals. This varies by condition and population.
While admitted patient care for intentional self-harm and very acute mental health-related conditions is most often provided by public hospitals following presentation to the emergency department, private hospitals provide a significant component of admitted patient care, particularly for less acute mental health, and alcohol and other drug-related conditions. For instance, more admitted patient care for depressive episodes and mental and behavioural disorders due to alcohol and other drug use is provided by private hospitals (see Admitted patients mental health-related care).
Private hospital services are not universally available and are most commonly funded by the patient’s private health insurance and/or self-funding - meaning that people from higher socioeconomic groups have higher rates of private hospital admissions. Private hospital care is also available through workers compensation arrangements, the Department of Defence for serving ADF members and the Department of Veterans’ Affairs for eligible ex-serving members. This is an important consideration as there are important sociodemographic differences associated with the aetiology and trajectory of mental health and alcohol and other drug-related conditions.
To accommodate the potential bias due to the lack of national private hospital data – 2 analyses are reported:
Analysis 1: This includes admitted patient care provided by public hospitals in NSW, Victoria, South Australia, Queensland, Tasmania, Australian Capital Territory (and in Western Australia and Northern Territory for eligible DVA clients) as a combined Australian total. This analysis provides insights into generally more acute and urgent admitted patient care for conditions related to suicide and can be accessed by all eligible Australians via Medicare.
Analysis 2: The Queensland analysis enables a more complete picture by including both the acute care that public and private hospitals provide, and the related rehabilitation and prevention programs more commonly provided by private hospitals. As Queensland was the only jurisdiction that had complete public and private hospital admissions which means that the analysis was conducted as a case study to better understand the downward bias that was present in Analysis 1.
Person-Level Integrated Data Asset (PLIDA)
The Person-Level Integrated Data Asset (PLIDA) formerly known as the Multi-Agency Data Integration Project is a partnership among Australian Government agencies to develop a secure and enduring approach for combining information on healthcare, education, government payments, personal income tax and population demographics. This analysis extracted demographic information about the ex-serving ADF member population and the comparator Australian population from the 2016 Census of Housing and Population and personal income tax data for the 2015-16 financial year. PLIDA is managed under the custodianship of the Australian Bureau of Statistics and more information is available on the ABS website.