Use of hospitals and homelessness services by refugees and humanitarian entrants

The NHMD is a compilation of episode-level records from admitted patient morbidity data collection systems in Australian public and private hospitals.

The counting unit in the NHMD is a separation, referred to as a hospitalisation in this report. Separation is the term used to refer to the episode of admitted patient care, which can be a total hospital stay (from admission to discharge, transfer or death) or a portion of a hospital stay beginning or ending in a change of type of care (for example, from acute care to rehabilitation).

Although hospital separations data are a valuable source of information about admitted patient care, they have limitations as indicators of ill health. Sick people who are not admitted to hospital are not counted and those who have more than 1 separation in a reference year are counted on each occasion. Therefore, these data count episodes of care, not patients.

The hospital separations data do not include episodes of non-admitted patient care provided in outpatient clinics or emergency departments. However, patients in these settings may be admitted subsequently, with the care provided to them as admitted patients being included in the NHMD.

The NNAPEDCD provides information on the care provided (including waiting times for care) for non-admitted patients registered for care in public hospital emergency departments that have:

• a purposely designed and equipped area with designated assessment, treatment, and resuscitation areas.
• the ability to provide resuscitation, stabilisation, and initial management of all emergencies.
• the availability of medical staff in the hospital 24 hours a day.
• designated emergency department nursing staff 24 hours per day 7 days per week, and a designated emergency department nursing unit manager.

Emergency departments (including ‘accident and emergency’ or ‘urgent care centres’) that do not meet the criteria above are not in scope for the NNAPEDCD, but data may have been provided for some of these by some states and territories.

Diagnosis data for hospital separations is presented using the 11^th edition of the International statistical classification of diseases and related health problems, 10th revision, Australian modification (ICD-10-AM). Mapping was undertaken to update the recorded principal diagnosis from the 9^th edition used for 2016–17 data and the 10^th edition used for 2017–18 and 2018–19 data to ensure all data presented aligns with the ICD-10-AM 11^th edition coding.

Diagnosis information for emergency department presentations were reported using the Emergency Department ICD-10-AM principal diagnosis shortlist. The 10^th edition was used for data in 2018–19 and the 11^th edition for data in 2019–20 and 2021–22. 2018–19. Diagnosis information prior to this used different classifications and is not presented in this report.

In tables and figures presenting information on diagnoses and external causes, the codes and abbreviated descriptions of the ICD-10-AM classification or ED shortlist are used. Edits have been made to the descriptions where necessary for length and clarity. Full descriptions of the categories and included diagnosis are available in ICD-10-AM and ED ICD-10-AM version 11 shortlist publications on the Independent Health and Aged Care Pricing Authority website - IHACPA.

The denominators for migrant groups were derived from the linkage of the SDB to the MCD. The SDB was linked to the MCD to identify the humanitarian entrants and other permanent migrants recorded on the MCD in the study period (see section Identifying presence in the reporting period). From this, the number of people in the study cohort within a financial year can be derived and person time then calculated for the denominator. If a person is in the cohort for the full financial year they contribute 1 to the denominator. The contribution to the denominator for people in the cohort for less than the full financial year is calculated from the month they entered or left the cohort. For example, a person who arrived in December of the financial year is only present for 7 of the 12 months in that financial year so their contribution to the denominator is 0.58 (7/12). Similarly, if a person dies in August, two months into the financial year, they will only contribute 0.17 (2/12) to the denominator. The sum of all person time within the financial year is the hospital analysis denominator for that financial year.

Age groups for the hospital analysis denominator are calculated using the age at 31 December of the financial year.

Time of presentation analysis

The time and weekday of presentation is based on the day of week and presentation time variables recorded in the NAPCEDCD. Presentation time is the time of first recorded contact with an emergency department staff member, which may be at the start of clerical registration or of the triage process. 

Arrival mode analysis

The arrival model is the mode of transport by which the person arrives at the emergency department as recorded in the NNAPEDCD. The other category includes people arriving by private transport, public transport and by walking.

Lower urgency care

In this data release, National Healthcare Agreement (NHA) indicator, Rate of GP style emergency department presentations, is referred to as ED presentations for lower urgency care. It is based on the NHA specifications ‘PI 19: Selected potentially avoidable GP-type presentations to emergency departments’.

ED presentations for lower urgency care are defined as presentations to public hospital emergency departments with a Type of visit of Emergency presentation where the patient:

• was allocated a Triage category of 4 (Semi-urgent: within 60 minutes) or 5 (Non-urgent: within 120 minutes) and
• did not arrive by ambulance, or police or correctional vehicle and
• was not admitted to the hospital, not referred to another hospital, or did not die.

Presentations without a mode of arrival or episode end status excluded in this ED presentations for lower urgency care measure.

Hospitalisations for injury

This report counts and describes injury incidents that result in a hospital admission or an emergency department presentation. A person may have more than one incident of injury resulting in hospitalisation in a financial year and each case of hospitalisation will be counted separately in this report; this is because we are counting incidents of injury resulting in hospitalisation, rather than the number of people who were hospitalised, in a given financial year.

Each record in the NHMD refers to a single episode of care in a hospital. Some injury incidents result in more than one episode of care and, hence, more than one record.

This can occur in 2 main ways:

• a person is admitted to one hospital, then transferred to another or has a change in care type (for example, from acute to rehabilitation) within the same hospital
• a person has an episode of care in hospital, is discharged home (or to another place of residence) and is later admitted for further treatment for the same injury, to the same hospital or another.

The NHMD does not allow for the identification of multiple episodes of care belonging to the same instance of injury. This means there is the potential for overcounting injury events if we are simply counting the number of injury episodes of care. To minimise this, the mode of admission is taken into account. Episodes of care with a mode of admission of transferred from another hospital (1) are excluded from injury case counts. This is because transfers are likely to have been preceded by an episode of care that already met the case selection criteria. Similarly, episodes of care where the mode of admission is statistical admission – episode type change (2) and the care type is not listed as acute (1, 7.1, 7.2), are also excluded as they are likely to have been preceded by an acute episode of care that already met the case selection criteria. Additional, records where Care involving use of rehabilitation procedures (Z50) has been coded in any additional diagnosis field, are excluded from this analysis to prevent counting of hospitalisations for rehabilitation.

This process largely corrects for overestimation of cases due to transfers (both internal and external) but does not correct for overestimation due to re-admissions.

The external cause classification (Chapter 20 of ICD-10-AM) consists of 3-character category codes in the range of U50–Y98 (including place of occurrence and activity when injured). The NHMD is structured so that the first listed external cause for a record relates to the first listed injury diagnosis. The first reported external cause is taken to be the nominal external cause for this analysis. The categorisation of external causes using ICD-10-AM codes are detailed in Appendix tables to Technical notes for Injury in Australia.

This analysis includes counts of injury in the category Complications of surgical and medical care (T80 – T88). This is excluded from standard AIHW injury reporting.

Emergency department presentations for injury

All emergency department presentations with a primary diagnosis ICD-10-AM codes in the range S00–T88 using ‘Chapter 19 Injury, poisoning and certain other consequences of external causes’, are included in this analysis.

Due to differences in state/territory data collection, no nationally comparable external cause data are available for NNAPEDCD records.

Hospital separations for selected conditions are considered to be ‘potentially preventable hospitalisations’ as they are amenable in some circumstances to primary and community care interventions. These conditions reflect the National Healthcare Agreement: Performance Indicator 18-Selected potentially preventable hospitalisations, 2022 and are categorised as being:

• acute (conditions that usually come on suddenly, and may not be preventable, but may not result in hospitalisation if timely and adequate care had been received in the community)
• vaccine-preventable (hospitalisations due to conditions that can be prevented by vaccination)
• chronic (conditions that are persistent and long-lasting but may be preventable through lifestyle change, and can also be managed in the community to prevent worsening of symptoms or hospitalisation).

Primary and community health care – including care from a general practitioner or community health nurse – can effectively manage and treat these health conditions (for example, by administering vaccines or prescribing lifestyle changes). Primary and community health care can be an opportunity for early intervention, which can help to reduce the risk of a person developing a disease, their symptoms worsening, or complications developing, to the point that they need hospitalisation.

Potentially preventable hospitalisations (PPH) can tell us about the effectiveness of health care in the community, as higher rates may suggest a lack of timely, accessible, and adequate primary care.

However, there are many other reasons why an area or group of people may have higher rates of PPH. These may include:

• higher rates of disease
• lifestyle factors and other risks
• a genuine need for hospital services.

Some PPH may not be avoidable, such as those for patients with complex illness, or patients having procedures as follow-up to primary care.

This means that it is important not to assume that higher rates of PPH always indicate a less effective primary care system. Rather, PPH are a useful tool for identifying and investigating variation between different groups of people to better understand health inequalities. PPH can help guide research about how different groups use and respond to health services, including barriers they may face and areas of unmet demand.

For more information on how PPH are defined and what conditions are included see the What are potentially preventable hospitalisations? Section of the AIHW’s Potentially preventable hospitalisations in Australia by small geographic areas, 2020–21 to 2021–22 web report.

Method of birth was derived from the primary diagnosis of the hospitalisations as classified in the ICD-10-AM (Table 2). Codes from O80–O84 are assigned when delivery is completed within the episode of care (for classification purposes delivery is not complete until after expulsion of the placenta, excluding any retained portion(s), expelled or requiring removal post delivery).

Source: International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM)

This classification differs from other AIHW reports which source data from the National Perinatal Data collection (NPDC). Births in this report only include those that occur in hospitals which are in scope for the NHMD. This will not include births that occur in birth centres, in the community or free births.

These analyses do not include information on the outcome of birth.