Spinal injuries in Australia 2020-21

Spinal injury hospitalisations in Australia, 2020–21: about the data

This report counts and describes injuries to the spine that lead to hospital admission, classified by cause. 

For ease of reading, in this report cases of hospitalisations for injury are referred to as ‘spinal injury hospitalisations’. However, throughout this technical note we have referred to a ‘case’ of hospitalisation for injury. This is deliberate to differentiate our count of injury hospitalisations from the usual counting unit for hospital patients which is a ‘separation’. A single incident of injury may result in multiple consecutive hospital separations, which we count as one ‘case’ of hospitalisation to represent the one incident of injury. 

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 due to injury, in a given financial year.

Scope

The aim of this report is to count the number of spinal injury hospitalisations in Australia from 1 July 2020 to 30 June 2021, inclusive. In all cases, patients had a principal or additional spinal injury diagnosis code in their hospitalisation record.

Only a small proportion of all incidents of injury result in admission to a hospital. For each admission, many more people with injuries are treated in an emergency department but are not admitted, or visit a general practitioner, allied health provider (for example, a physiotherapist) or Urgent Care/Walk-in Clinic rather than a hospital. A larger number of minor injuries do not receive any medical treatment. A smaller number of severe injuries that result in death do not include a stay in hospital but are captured in mortality data. 

This document covers: 

• definitions and classifications used 
• presentation of data in this report 
• analysis methods. 

Data sources

The data on hospitalised injury cases are from the Australian Institute of Health and Welfare’s (AIHW) National Hospital Morbidity Database (NHMD). The NHMD is a compilation of episode-level records from admitted patient morbidity data collection systems (APC NMDS) in Australian public and private hospitals. The scope of the APC NMDS is episodes of care for admitted patients in all public and private acute and psychiatric hospitals, free standing day hospital facilities and alcohol and drug treatment centres in Australia. Hospitals operated by the Australian Defence Force, corrections authorities and in Australia's off-shore territories may also be included. Hospitals specialising in dental, ophthalmic aids and other specialised acute medical or surgical care are included. This report may therefore be viewed as a definitive description of all injury cases admitted to hospitals in Australia. Comprehensive information on the quality of data is available on the AIHW MyHospitals website.

Admitted patient care data

In the NHMD, records are presented by hospital separations (discharges, transfers, deaths, or changes in care type) by time period. Records from any selected period will include data on patients who were admitted before that period— if they separated during that period. A record is included for each separation, not each patient, so patients who separated more than once in the period will have more than one record. 

Patient days is the number of days between the separation date and date of admission, not including any hospital leave days. Patient day statistics can provide information on hospital activity that, unlike separation statistics, accounts for differences in length of stay.   

It is expected that patient days for patients who separated in 2020–21, but who were admitted before 1 July 2020, will be counterbalanced overall by the patient days for patients in hospital on 30 June 2021 who will separate in future reporting periods.

Estimated resident populations 

All populations are based on the estimated resident population (ERP) or Indigenous projected population as at 30 June immediately prior to the reporting period (that is, for the reporting period 2020–21, the population at 30 June 2020 is used). The population is used as the denominator for age‑specific/crude and age‑standardised rates.

The ERP as at 30 June 2001 is used as the standardising population throughout the report (ABS 2003).

The COVID-19 pandemic and resulting Australian Government closure of the international border from 20 March 2020 disrupted the usual Australian population trends. The ERP for 30 June 2020, used in this report, reflects this disruption.

All population data are sourced from the Australian Bureau of Statistics (ABS) as follows:

• General populations are from National, state and territory population (Australian Bureau of Statistics 2023, March)
• Indigenous populations are from Estimates and Projections, Aboriginal and Torres Strait Islander Australians (ABS 2019)
• Remoteness populations (available on request from ABS)
• Socio-Economic Indexes For Areas (SEIFA) Index of Relative Socio-Economic Disadvantage (IRSD) quintile populations are from AIHW analysis of Census of Population and Housing: Socio-Economic Indexes for Areas (ABS 2018) and Regional population (Australian Bureau of Statistics 2022).

Estimating cases of injury

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.

Please see Injury in Australia hospitalisations Technical Notes for further details.

Selection criteria

The following criteria were used to estimate numbers of cases of spinal injury hospitalisations in Australia, by cause of injury. 

Period

Selection was based on the financial year of separation, from 1 July 2020 to 30 June 2021. 

Standard separations

Standard separations were included, that is records were excluded where the care type was newborn with unqualified days only (7.3), organ procurement - posthumous (9), or hospital boarder (10).

Spinal injury

For the purposes of this report, spinal injury cases are defined as records meeting either of the criteria below:

1. principal diagnosis in the ICD-10-AM range S12.0-S12.2, S12.7, S12.9, S13.0-S13.3, S13.4, S14.0-S14.7, S15.1, S22.0, S22.1, S23.0, S23.1, S23.3, S24.0, S24.1-S24.7, S32.0-S32.2, S32.7, S32.82, S33.0, S33.1, S33.2, S33.5, S33.6, S34.0-S34.5, S34.7, T06.0, T06.1, T08, T09.3, T09.4 using ‘Chapter 19 Injury, poisoning and certain other consequences of external causes’,  or
2. additional diagnosis in the ICD-10-AM range S12.0-S12.2, S12.7, S12.9, S13.0-S13.3, S13.4, S14.0-S14.7, S15.1, S22.0, S22.1, S23.0, S23.1, S23.3, S24.0, S24.1-S24.7, S32.0-S32.2, S32.7, S32.82, S33.0, S33.1, S33.2, S33.5, S33.6, S34.0-S34.5, S34.7, T06.0, T06.1, T08, T09.3, T09.4.

This scope excludes injuries due to Complications of surgical and medical care (T80 – T88) and Sequelae of injuries, of poisoning and of other consequences of external causes (T90 – T98).

Records where Care involving use of rehabilitation procedures (Z50) has been coded in any additional diagnosis field are excluded from this analysis, except if the care type for the separation was acute. Nearly all injury separations are thought to be included in the data reported, representing minimal risk of counting error.

External causes 

Please see Injury in Australia hospitalisations Technical Notes Appendix tables for further details. 

Presentation of data and analysis

Due to rounding, percentages in tables may not add up to 100.0. Percentages and rates reported as 0.0 or 0 usually indicate a zero. 

Spinal region and injury type analysis contain principal diagnosis cases only. 

The patient’s age is calculated at the date of admission. In tables by age group and sex, separations for which age and/or sex were not reported are included in the totals. Refer to the Injury in Australia technical notes for more information.

For descriptions of the approach to suppression as well as analysis methods for length of stay, age-standardised rates and remoteness, refer to Injury in Australia Technical Notes.

Definitions and classifications

If not otherwise indicated, data elements were defined as per their definitions in the AIHW’s Metadata Online Registry (METeOR, https://meteor.aihw.gov.au/content/181162) and summarised in the Glossary (AIHW 2023).

In particular, data element definitions for the Admitted patient care National Minimum Data Set (NMDS) are available at: https://meteor.aihw.gov.au/content/713850 (AIHW 2021).

Injury classifications from ICD-10-AM/ACHI

Diagnosis, intervention and external cause data for 2020–21 was reported to the NHMD by all states and territories using classifications from the 11^th edition of the International statistical classification of diseases and related health problems, 10^th revision, Australian modification (ICD-10-AM) (ACCD 2019a).

In tables and figures, information on diagnoses, external causes, and interventions are presented using the codes and abbreviated descriptions of the ICD-10-AM and the 11th edition of the Australian classification of health interventions (ACHI). Full descriptions of the categories are available in ICD-10-AM/ACHI publications (ACCD 2019a, ACCD 2019b, ACCD 2019c). Some injury cases do not include an external cause (falls, transport, assault, etc.), or the only cause code provided is invalid for the scope of this report (i.e., supplementary factor codes). These cases are included in this report as ‘not reported’ and are counted towards to the total injury cases.

Where data are presented in a time series incorporating previous reporting periods, 
 these have been coded according to the following editions of ICD‑10‑AM:

• 7^th edition for 2011–12 and 2012–13 hospital data
• 8^th edition for 2013–14 and 2014–15 hospital data
• 9^th edition for 2015–16 and 2016–17 hospital data
• 10^th edition for 2017–18 and 2018–19 hospital data
• 11^th edition for 2019–20 hospital data.

This report simplified the most common ICD-10-AM codes and ACHII chapter procedure types into plain English terms. Simplified plain English ICD-10-AM codes are shown in Table 1.

Table 1: ICD-10-AM codes used to report principal diagnoses

The ACHI procedure chapters and the code ranges covered by each under Edition 10 of the ACHI are available on the Procedures data cubes page.