Appendix C: Analysis variables
Access to specialist palliative care services is influenced by demographic, geographical, socioeconomic, and clinical factors. As such, some population groups have greater barriers/challenges to accessing services. This section defines the variables used in this report to explore these issues.
C.1 Place of death
Place of death is presented for 4 settings of care – people who, at the time of death, were in hospital inpatient care, ED, residential aged care, or other settings. Other settings capture all deaths (from total deaths) that did not occur in hospitals, ED or residential aged care. Where an individual has a different place of death recorded across the datasets in NIHSI, a set of hierarchical rules were developed with priority given to ED, followed by admitted patient in hospital, residential aged care, and other settings.
For disaggregation by diagnosis, people who died in ED or ‘other’ settings were grouped together (as ‘ED-other’) to preserve confidentiality (due to small counts).
C.2 Time from receipt of service to death
To identify when a service was initiated and ceased, the number of days from first or last receipt of a service to death were calculated. These are presented as both:
- time intervals, grouped as days between first/last service receipt to death – 0–7 days, 8–14 days, 15–29 days, 30–90 days, 3–6 months (91–182 days) and 6–12 months (183–365 days)
- mean and median number of days from receipt of first/last service to death. Note this report mainly presents information on the median due to skew in the distributions; however, the supplementary tables include both the mean and median.
Note that hospital data was based on date of admission and not date of separation or discharge.
C.3 Diagnosis
A range of measures were used to examine whether service use varies by diagnosis. Diagnosis was described using the following methods:
- Cause of death based on the underlying causes of death for specific causes, as outlined in Appendix Table A3 and Appendix B.
- End of life disease trajectories based on the underlying cause of death, as per the conditions specified in Appendix Table A2.
- Principal diagnosis at last hospital admission prior to death based on conditions listed in Appendix Table A3. Note that not all people hospitalised with these conditions died from the same condition.
Due to small counts, renal failure was grouped with liver failure and HIV included under “Other” conditions.
Note:
- The underlying cause of death, identified from Part 1 of the death certificate, is the disease or injury that initiated the train of events leading directly to death.
- Principal diagnosis is diagnosis established after study to be chiefly responsible for occasioning an episode of admitted patient care (hospitalisation). Hospital admissions with a care type reported as Newborn with no qualified days, hospital boarders, and posthumous organ procurement were excluded from the analysis, as per standard AIHW reporting.
C.4 Interventions
Specific interventions were also examined using inpatient hospital procedures (chemotherapy and dialysis) and MBS-subsidised pathology and diagnostic imaging services in non-hospital settings (see Appendix Table A1 for listing of procedure codes):
- Chemotherapy (including radiotherapy and immunotherapy) is defined using a range of procedure codes in the Admitted Patient Care dataset within NIHSI.
- Dialysis is defined using a range of procedures codes in the Admitted Patient Care dataset within NIHSI.
- Pathology services, from the MBS dataset, include tests of patient samples, such as blood, urine, stools, or body tissues. Note that one sample may result in multiple tests and therefore multiple MBS services.
- Diagnostic imaging services, from the MBS dataset, including X-rays, CT scans, ultrasound scans, MRI scans and nuclear medicine scans.
C.5 Emergency Department presentations
ED presentations in the last year of life included 'emergency' presentations and 'planned' presentations (such as a planned review or a planned admission to hospital via the ED). Analysis on ED presentations that were subsequently admitted to hospital was restricted to ‘emergency’ presentations only.
C.6 Palliative care-related prescriptions
Palliative care-related prescriptions are defined based on clinically meaningful groupings of medications to treat common palliative care symptoms – pain relief, gastrointestinal symptoms, neurological symptoms, respiratory symptoms, and psychological symptoms. See AIHW (2023) for further details on the ATC codes used for these medications. Information is presented for the PBS Palliative Care Schedule and other schedules (General Schedule, Repatriation Pharmaceutical Benefits Scheme data and other schedules combined).
C.7 Remoteness
The 2016 Australian Statistical Geographical Standard for Remoteness Areas (ASGS), developed by the Australian Bureau of Statistics (ABS), is used to report on 5 remoteness categories – Major cities, Inner regional, Outer regional, Remote, Very remote.
In this report, Remote/Very remote areas have been excluded from the analysis as 52% of the population living in remote/very remote areas reside in WA and the NT. These 2 jurisdictions are not included in the hospital datasets (NIHSI Version 2).
C.8 Socioeconomic status
The Socio-Economic Indexes for Areas (SEIFA) Index of Relative Socio-Economic Disadvantage (IRSD) was used to assess whether characteristics vary by socioeconomic status. The IRSD was developed by the ABS and represents the socioeconomic position of Australian communities. It measures aspects of disadvantage, such as low income, low educational attainment, high unemployment, and jobs in relatively unskilled occupations. Areas are then ranked by their level of disadvantage.
Note that the IRSD reflects the overall or average socioeconomic position of the population of an area; it does not show how individuals living in the same area might differ from each other.