In cases where the cause of injury is known but it is not clear if the act was accidental or intentional, hospital and death records can be coded to identify that the intent was undetermined.

In 2019–20, injuries of undetermined intent resulted in about:

4,400 hospitalisations

17.4 per 100,000 population

 260 deaths

1.0 per 100,000 population

This represents 0.8% of injury hospitalisations and 2% of injury deaths.

Causes of hospitalisation

The most frequent causes of injury hospitalisations of undetermined intent in 2019–20 were various kinds of poisoning, and contact with blunt objects (Table 1).

Table 1: Causes of injury hospitalisations of undetermined intent, 2019–20

Cause

Number

%

Rate
(per 100,000)

Poisoning by and exposure to antiepileptic, sedative-hypnotic, antiparkinsonism and psychotropic drugs, not elsewhere classified (Y11)

1,057

24

4.1

Poisoning by and exposure to narcotics and psychodysleptics [hallucinogens], not elsewhere classified (Y12)

861

19

3.4

Other poisoning (Y10, Y13–Y19)

1,066

24

4.1

Total poisoning (Y10–Y19)

2,984

67

11.6

Contact with blunt objects (Y29)

659

15

2.6

Other (Y20–Y28, Y30–Y34)

793

18

3.2

Total

4,436

100

17.4

Notes

  1. Rates are crude per 100,000 population.
  2. Percentages may not total 100 due to rounding.
  3. Codes in brackets refer to the ICD-10-AM (11th edition) external cause codes (ACCD 2019).

Source: AIHW National Hospital Morbidity Database.

For more detail, see Data tables B33–34.

Causes of death

The most frequent causes of injury death in this category in 2019–20 were various kinds of poisoning (Table 2).

Table 2: Causes of injury deaths of undetermined intent, 2019–20

Cause

Number

%

Rate
(per 100,000)

Poisoning (Y10–Y19)

131

51

0.5

Hanging, strangulation, suffocation, drowning and submersion (Y20-Y21)

23

9

0.1

Crashing of motor vehicle (Y32)

23

9

0.1

Other (Y22–Y31, Y33–34)

82

32

0.3

Total

259

100

1.0

Notes

  1. Rates are crude per 100,000 population.
  2. Percentages may not total 100 due to rounding.
  3. Codes in brackets refer to the ICD-10 external cause codes (WHO 2011).

Source: AIHW National Mortality Database.

For more detail, see Data tables E45–47.

Seasonality and COVID-19

Hospital admissions due to injuries of undetermined intent do not appear to exhibit a seasonal pattern, remaining relatively steady throughout the year.

In March 2020, the first lockdowns and social distancing measures associated with COVID-19 interrupted the usual activity of many Australians. It’s not clear if COVID-19 had a particular effect on the number of admissions to hospital with injuries of undetermined intent. There were 2.7% more cases from March to May than the same period of the previous year (Figure 1).

See the interactive COVID-19 display for data and further discussion about the impact of COVID-19 on hospital admissions.

Figure 1: Injury hospitalisations of undetermined intent by month, 2017–18 to 2019–20

Notes

  1. Months have been standardised to 31 days.
  2. A scale up factor has been applied to June admissions to account for cases not yet separated.

Source: AIHW National Hospital Morbidity Database.

Variation by age and sex

Rates of hospitalised injury of undetermined intent in 2019–20 were highest in the 15–24 age group, and higher for males. Rates of death were highest in the 25–44 age group (Figure 2):

Figure 2: Injury hospitalisations and deaths of undetermined intent, by age group and sex, 2019–20

The visualisation features 2 matching column graphs on separate tabs, 1 for hospitalisations and 1 for deaths. The columns represent sex within 6 life-stage age groups. The reader can select to display either age-specific rate per 100,000 population or number. The default displays males and females and the reader can also select to display persons.

For more detail, see Data tables A1–3 and D1–3.

Severity

There are many ways that the severity, or seriousness, of an injury can be assessed. Using available data, three measures of the severity of hospitalised injuries are:

  • number of days in hospital
  • time in an intensive care unit (ICU)
  • time on a ventilator.

The average number of days in hospital for injuries in this category was less than the average for all hospitalised injuries, but the percentage of cases that included time in an ICU or involved continuous ventilatory support were much higher than for all hospitalised injuries in 2019–20 (Table 3).

Table 3: Severity of injury hospitalisations of undetermined intent, 2019–20

 

Undetermined intent

All hospitalised injuries

Average number of days in hospital

2.4

4.5

% of cases with time in an ICU

12.3

2.4

% of cases involving ventilator

10.0

1.4

Note: Average number of days in hospital (length of stay) includes admissions that are transfers from 1 hospital to another or transfers from 1 admitted care type to another within the same hospital, except where care involves rehabilitation procedures.

Source: AIHW National Hospital Morbidity Database.

Aboriginal and Torres Strait Islander people

In 2019–20, among Aboriginal and Torres Strait Islander people:

  • there were 457 hospitalisations and 14 deaths of undetermined intent (Tables 4 and 5)
  • males had higher rates of hospitalisation
  • hospitalisation rates were highest among people aged 25–44, compared with other age groups (Figure 3).
Table 4: Number and rate of injury hospitalisations of undetermined intent by sex, Indigenous Australians, 2019–20

 

Males

Females

Persons

Number

262

195

457

Rate (per 100,000)

61

46

54

Note: Rates are crude per 100,000 population.

Source: AIHW National Hospital Morbidity Database.

Table 5: Number and rate of injury deaths of undetermined intent by sex, Indigenous Australians, 2019–20

 

Males

Females

Persons

Number

7

7

14

Rate (per 100,000)

1.9

1.9

1.9

Notes

  1. Rates are crude per 100,000 population.
  2. Deaths data only includes data for New South Wales, Queensland, Western Australia, South Australia, and the Northern Territory.

Source: AIHW National Mortality Database.

Indigenous and non-Indigenous Australians

In 2019–20, Indigenous Australians were 3.7 times as likely as non-Indigenous Australians to be hospitalised with injuries of undetermined intent (Table 6).

Table 6: Age-standardised rates (per 100,000) of injury hospitalisations of undetermined intent by Indigenous status and sex, 2019–20

 

Males

Females

Persons

Indigenous Australians

66

52

59

Non-Indigenous Australians

19

13

16

Notes

  1. Rates are age-standardised per 100,000 population.
  2. ‘Non-Indigenous Australians’ excludes cases where Indigenous status is missing or not stated.

Source: AIHW National Hospital Morbidity Database.

The age-specific rate of injury hospitalise of undetermined intent was highest among the 25–44 life-stage age group for Indigenous Australians and the 15–24 age group for non-Indigenous Australians (Figure 3). Deaths data are not presented because of small numbers.

Figure 3: Injury hospitalisations of undetermined intent, by Indigenous status, by age group and sex, 2019–20

The visualisation features a column graph for hospitalisations. The columns represent data for Indigenous and non-Indigenous Australians by 6 life-stage age groups. The reader can select to display age-specific rate per 100,000 population or number. The reader can also select to display data for persons, males or females.

For more detail, see Data tables A4–A6 and D4–D8.

Remoteness

In 2019–20, people living in Remote areas, compared with people living in Major cities, were:

  • 1.7 times as likely to be hospitalised due to injuries of undetermined intent (Table 7)
Table 7: Age-standardised rates (per 100,000) of hospitalisations of undetermined intent by remoteness and sex, 2019–20

 

Males

Females

Persons

Major cities

19

13

16

Inner regional

22

15

19

Outer regional

25

18

22

Remote

33

22

28

Very remote

26

26

26

Note: Rates are age-standardised per 100,000 population.

Source: AIHW National Hospital Morbidity Database.

The highest age-specific rate of hospitalisations of undetermined intent was among the 15–24 age group living in Remote areas of Australia. (Figure 4).

Deaths data are not presented here because of small numbers.

Figure 4: Hospitalisations of undetermined intent, by remoteness, by age group and sex, 2019–20

The visualisation features a column graph for hospitalisations. The columns represent data for each of the 5 remoteness categories by 6 life-stage age groups. The reader can select to display age-specific rate per 100,000 population or number. The reader can also select to display data for persons, males or females.

For more detail, see Data tables A7–9 and D9–10.

For information on how statistics by remoteness are calculated, see the Technical notes.

More information

Defining injury hospitalisations and deaths: how injuries were counted

Technical notes: how the data were calculated

Data tables: download the full tables

Glossary