Sports injury in Australia

Hospitalisations data are sourced 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. It includes 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 offshore territories may also be included. Hospitals specialising in dental, ophthalmic aids and other specialised acute medical or surgical care are included. Data quality statements for the NHMD are available on the AIHW MyHospitals website. For more information about data contained in the NHMD refer to the AIHW MyHospitals technical notes.

Population data are used for demographic analyses and as the denominator in calculating rates. All population level calculations are based on the estimated resident population (ERP) calculated as at the midpoint of each financial year. For example, for the reporting period 2021–22, the denominator population is the June 2021 ERP + the June 2022 ERP, divided by 2.  This 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).

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

• General populations are from National, state and territory population
• First Nations populations are from Estimates and Projections, Aboriginal and Torres Strait Islander Australians (ABS 2019)
• Remoteness populations (available on request from ABS).

AusPlay data is collected on behalf of Sport Australia. Australian residents are randomly selected using their mobile phone number and interviewed via a computer assisted telephone interview (CATI). The target sample size is 20,000 people aged 15 years and over. The survey period for the 2021–22 data is 1 July 2021 to 30 June 2022.

The sample data is projected to population estimates using a common post-stratified weighting (scaling) method. As the survey estimates are based on a sample, rather than the full population, they will have sample error. One measure of the sample error is the relative margin of error (RMOE). Survey estimates with a RMOE between 50% and 100% should be used with caution. Survey estimates with a RMOE greater than 100% are considered too unreliable to use.

AusPlay survey respondents answer questions about their participation in sports and physical recreation in the 12 months prior to interview. A respondent needs only to have participated once in the previous 12 months to be counted as a participant. The survey does not distinguish between organised sports and recreational participation. For example, a participant in soccer may have played consistently in an organised competition over a six-month period or may have played soccer recreationally at a park with friends: both are treated equally as soccer participants.

• Records with the maximal snapshot id in any database where the date of separation falls between 1 July 2021 to 30 June 2022.
• NHMD records with a principal diagnosis in the ICD 10 AM range S00–T75 or T79, using ‘Chapter 19 Injury, poisoning and certain other consequences of external causes’.
• NHMD records with an activity code in the ICD 10 AM sports activity range U50–U71. For records where the first recorded activity code is Leisure activity, not elsewhere classified (U72) or While working for income (U73), then the second recorded activity code is considered.
• NHMD records with a separation date between 1 July 2021 to 30 June 2022.

• Records were excluded where the AIHW ‘standard analysis’ flag was absent, i.e. care type was newborn with unqualified days only (7.3), organ procurement - posthumous (9), or hospital boarder (10).
• 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) are excluded.

Cycling can be a sport, a recreation activity, or a mode of transport. For hospitalisations, information is recorded separately about the cause of the injury – which could be a cycling transport accident – and the activity being undertaken at the time of the injury – which could be cycling as a sport, a sport other than cycling, or a non-sport activity.

In this report, cycling sport injury hospitalisations include:

• a recorded activity of cycling as a sport, and the cause of injury was a cycling transport accident, or
• a recorded activity of cycling as a sport, but the cause of injury was not a cycling transport accident.

Hospitalisations where a recorded activity of a sport other than cycling, and the cause of injury was a cycling transport accident, are also included in this report as sport injury hospitalisations, but attributed to the recorded sport (which is not cycling).

Hospitalisations that had a cause of injury of a cycling transport accident, but the activity was non-sport (such as leisure, working, or other specified activity) are not included in this report.

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, therefore, more than one record. 

To minimise the impact of overcounting where a person experienced multiple episodes of care relating to the same condition, the following criteria are applied to estimate incidents:

• Excludes records where admission mode is transfer from another hospital (1)
• Excludes records where admission mode is statistical admission (2) and care type is not acute (1, 7.1, 7.2)
• Excluding records where care involving use of rehabilitation procedures (Z50) appears as an additional diagnosis and care type is not acute (1, 7.1, 7.2).

Diagnosis, intervention, activity, place of occurrence and external cause data for 2021–22 were reported to the NHMD using classifications from the 11th edition of the International statistical classification of diseases and related health problems, 10th revision, Australian modification (ICD-10-AM) (ACCD 2019a), incorporating the Australian classification of health interventions (ACHI).

In tables and figures, information on diagnoses, external causes, activity, place of occurrence and interventions are presented using the codes and abbreviated descriptions of the ICD-10-AM/ACHI. Full descriptions of the categories are available in ICD-10-AM/ACHI publications on the Independent Health and Aged Care Pricing Authority (IHACPA) website (ACCD 2019a, ACCD 2019b, ACCD 2019c).

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:

• 7th edition for 2011–12 and 2012–13 hospital data
• 8th edition for 2013–14 and 2014–15 hospital data
• 9th edition for 2015–16 and 2016–17 hospital data
• 10th edition for 2017–18 and 2018–19 hospital data
• 11th edition for 2019–20, 2020-21 and 2021–22 hospital data

The AusPlay sports categories are not an exact match to the sports categories for the hospital data. Table 1 below provides the AusPlay to ICD-10-AM mapping used for this report.

The NHMD is structured so that the first listed external cause for a record relates to the first listed injury diagnosis (principal diagnosis). While multiple external causes may be recorded for a separation, we report only one cause for each injury, referred to as ‘nominal external cause’ in these notes. The following steps are followed to determine the nominal external cause for each injury hospitalisation:

1. The first reported external cause is taken to be the nominal external cause
2. If the nominal external cause, as determined by step 1, is U90.0 (Staphylococcus aureus) or a supplementary factor (Y90–Y98), then the second reported code is taken to be the nominal external cause
3. If the nominal external cause, after steps 1 and 2, relates to complications of medical and surgical care (Y40–Y84), sequelae of external causes of morbidity and mortality (Y85–Y89), or a supplementary factor code (Y90–Y98), then the record is excluded.

The categorisation of external causes using ICD-10-AM codes are detailed in Appendix tables to technical notes for Injury in Australia. 

Type of injury and site of injury on the body is based on the patient’s principal diagnosis. Principal diagnosis is the diagnosis chiefly responsible for occasioning the episode of care for the patient as defined by ICD-10-AM codes. The principal diagnosis details the type of injury sustained such as fractures, dislocations, nerve injuries and burns, and the body part injured such as head, neck, ankle and foot. 

To categorise injuries by type and body part injured, Injury in Australia’s principal diagnosis matrix has been applied (as outlined in the Appendix tables to technical notes for Injury in Australia). 

The sum of injuries by body part may not equal the total number of hospitalised injury cases because some injuries are not described in terms of body region.

The Australian ERP as at 30 June 2001 is used as the standardising population throughout the report. Age standardisation of rates enables valid comparison across years and/or jurisdictions without being affected by differences in age distributions. 

Population based rates of injury tend to have similar values from one year to the next. Exceptions to this can occur (for example, due to a mass casualty disaster), but are unusual in Australian injury data. Some year on year variation and short run fluctuations are to be expected, so small changes in a rate over a short period do not provide a firm basis for asserting that a trend is present.

Note that ‘average length of stay’, as presented in this report, does not include some patient days potentially attributable to injury. It does not include days for most aspects of injury rehabilitation, which cannot be reliably assigned without information enabling identification of all admitted episodes associated with an injury case.

Timeseries

10-year time series rates may not match historically published rates due to changes in denominator data over time, jurisdictional updates in numerator data or retrospective refreshing of numerator or denominator data across different data sources.

Remoteness

Remoteness areas are based off the patient’s usual place of residence and are defined using the ABS’ Australian Statistical Geography Standard (ASGS) Remoteness Structure 2016 (ABS 2016). The ASGS Remoteness Structure 2016 categorises geographical areas in Australia into remoteness areas, described in detail on the ABS website which also includes detail of the nature of changes between the ASGS 2011 and ASGS 2016.

The remoteness classification is as follows: 

• Major cities – for example, Sydney, Melbourne, Brisbane, Adelaide, Perth, Canberra and Newcastle
• Inner regional – for example, Hobart, Launceston, Wagga Wagga, Bendigo and Murray Bridge
• Outer regional – for example, Darwin, Moree, Mildura, Cairns, Charters Towers, Whyalla and Albany 
• Remote – for example, Port Lincoln, Esperance, Queenstown and Alice Springs 
• Very remote – for example, Mount Isa, Cobar, Coober Pedy, Port Hedland, Tennant Creek and Norfolk Island.

Counts are presented as whole numbers.

Crude/age-specific rates and age-standardised rates are calculated per 100,000 population or participants and are rounded to 1 decimal place.

Proportions (%) and ALOS are also rounded to 1 decimal place.

The AIHW operates under a strict privacy regime which has its basis in Section 29 of the Australian Institute of Health and Welfare Act 1987 (AIHW Act). Section 29 requires that confidentiality of data relating to persons (living and deceased) and organisations be maintained. The Privacy Act governs confidentiality of information about living individuals. The AIHW is committed to reporting that maximises the value of information released for users while being statistically reliable and meeting legislative requirements described in the AIHW Act and the Privacy Act.  Aggregated injury hospitalisations data are usually presented in tables, graphs, or maps. To maintain attribute disclosure and minimise risk of potentially re-identifying a person, data suppression rules have been applied.

Consequential suppression may also be applied to prevent a suppressed cell from being calculated. This is often done by suppressing table cells in the same row or column or suppressing the table totals.

Calculated data may also be suppressed due to quality and reliability reasons.

Counts

• Counts less than 5 are suppressed and consequential suppression is applied.
• When data are disaggregated by geography location, counts for areas where the population is less than 1,000 are suppressed.

Crude rates

• Crude rates with counts (numerator for calculation) less than 10 are suppressed.
• If the corresponding counts measure is suppressed, the crude rate has been suppressed.
• When data are disaggregated by geography location, counts for areas where the population is less than 100 are suppressed.

Age-standardised rates

• Age-standardised rates with counts (numerator for calculation) less than 20 are suppressed.
• If the corresponding counts measure is suppressed, the age-standardised rate has been suppressed.
• When data are disaggregated by geography location, counts for areas where the population is less than 30 are suppressed.

Z-score

No suppression applied.

A summary of data notes and data quality issues for the NHMD can be found in the Admitted Patient Care technical notes and appendices on MyHospitals.

The key issues are:

First Nations status

The AIHW report Indigenous identification in hospital separations data: quality report (AIHW 2013) presents the latest findings on the quality of First Nations identification in hospital separations data in Australia, based on studies conducted in public hospitals during 2011. Private hospitals were not included in the assessment. The findings indicate that, overall, the quality of First Nations identification in hospital separations data was similar to that achieved in a previous study (AIHW 2010). However, the survey for the 2013 report was performed on larger samples for each jurisdiction/region and is therefore considered more robust than the previous study. An estimated 88% of First Nations patients were correctly identified in Australian public hospital admission records in 2011-12 (AIHW 2013). This under counting of First Nations patients is a known issue across states and territories with proportions ranging from 58% (confidence interval, 46-69%) in the Australian Capital Territory and 98% (96-99%) in the Northern Territory over the same time period.

Variation in state and territory coding practices

The emergency department admission policy was changed for New South Wales (NSW) hospitals in 2017–18. Episodes of care delivered entirely within a designated emergency department or urgent care centre are no longer categorised as an admission regardless of the amount of time spent in the hospital. This narrowing of the categorisation has had the effect of reducing the number of admissions recorded in NSW from the 2017–18 financial year. For NSW the effect was a significant decrease (3.7%) in all public hospital admissions in 2017–18 compared to 2016–17. The impact of the change was felt disproportionately among hospitalisations for injury and poisoning. According to NSW Health, the number of hospitalisations for injury and poisoning in NSW decreased by 7.6% between 2016–17 and 2017–18, compared to a usual yearly increase of 2.8% (Centre for Epidemiology and Evidence 2019).

The change in NSW’s emergency department admission policy may have had different effects on case numbers within different external cause categories. This is because different types of injury have a different likelihood of requiring prolonged care in an emergency department, but without an admission to a hospital ward.

Due to the size of the contribution of NSW data to the national total, Australian data from 2017–18 should therefore not be compared with data from previous years.

ABS (Australian Bureau of Statistics) (2003) Population by age and sex, Australian states and territories, 2001: Census edition final. ABS cat. no. 3201.0. Canberra: ABS.

ABS (2016) Australian Statistical Geography Standard (ASGS): Volume 5 – Remoteness structure, July 2016. ABS cat. no. 1270.0.55.005. Canberra: ABS.

ABS (2019) Estimates and projections, Aboriginal and Torres Strait Islander Australians, 2006 to 2031. ABS cat. no. 3238.0. Canberra: ABS.

ACCD (Australian Consortium for Classification Development) (2019a). The international statistical classification of diseases and related health problems, 10th revision, Australian modification (ICD-10-AM), 11th edn. Tabular list of diseases and alphabetic index of diseases. Adelaide: Independent Hospital Pricing Authority (IHPA), Lane Publishing.

ACCD (2019) The Australian classification of health interventions (ACHI), 11th edn. Tabular list of interventions and alphabetic index of interventions. Adelaide: IHPA, Lane Publishing.

ACCD (2019) The international statistical classification of diseases and related health problems, 10th revision, Australian modification (ICD-10-AM), 11th edn. Australian coding standards for ICD-10-AM and ACHI. Adelaide: IHPA, Lane Publishing.

AIHW (2013) Indigenous identification in hospital separations data: quality report. Cat. no. IHW 90. Canberra: AIHW.

WHO (World Health Organization) (2019.) The international statistical classification of diseases and related health problems, 10th revision (ICD-10) Geneva: WHO. Accessed 7 May 2024.