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.

Injuries of undetermined intent resulted in about:

3,900 hospitalisations in 2020–21

15 per 100,000 population

 260 deaths in 2019–20

1.0 per 100,000 population

This represents 0.7% of injury hospitalisations and 1.9% of injury deaths.

Causes of hospitalisation

The most frequent causes of injury hospitalisations of undetermined intent in 2020–21 were various kinds of poisoning, and contact with blunt objects (Table 1).

Table 1: Causes of injuries of undetermined intent, 2020–21 hospitalisations

Cause

Hospitalisations

%

Rate (per 100,000)

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

921

23

3.6

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

644

16

2.5

Other poisoning (Y10, Y13–Y19)

965

25

3.8

Total poisoning (Y10–Y19)

2,530

64

9.9

Contact with blunt objects (Y29)

667

17

2.6

Other (Y20–Y28, Y30–Y34)

740

19

2.9

Total

3,937

100

15.3

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.

Seasonal differences

Hospitalisations due to injuries of undetermined intent do not show an obvious seasonal pattern.

Some categories of injury do show a seasonal pattern – see the interactive display.

Figure 1: Seasonal differences in hospitalisations for injuries of undetermined intent, 2018–19 to 2020–21

Notes

  1. Admission counts have been standardised into two 15-day periods per month.
  2. A scale-up factor has been applied to June admissions to account for cases not yet separated.

Source: AIHW National Hospital Morbidity Database.

Trends over time

The age-standardised rate of hospitalisation for injuries of undetermined intent in 2020–21 was 12% lower than the previous year.

Over the period from 2011–12 to 2016–17 there was an average annual decrease of 3.8% for the age-standardised rate of hospitalisations.

There is a break in the time series for hospitalisations between 2016–17 and 2017–18, due to a change in data collection methods (see the Technical notes for details).

For deaths from injuries of undetermined intent, the age-standardised rate for 2019–20 was 4.9% higher than a year earlier. There was an average annual decrease in rate between 2010–11 and 2019–20 of 2.3% (Figure 2).

Figure 2: Hospitalisations and deaths from injuries of undetermined intent, by sex and year

2 matching line graphs on separate tabs, 1 tab for hospitalisations and 1 for deaths over 10 years. The 3 lines represent the trend for males, persons and females. The reader can choose to display rate per 100,000 population or number.

Visualisation not available for printing

For more detail, see Data tables C1–3 and F1–4 

Age and sex differences

Rates of hospitalisation for injuries of undetermined intent in 2020–21 were highest in the 15–24 age group, and higher for males. Rates of death in 2019–20 were highest in the 25–44 age group (Figure 3).

Figure 3: Hospitalisations and deaths from injuries of undetermined intent, by age group and sex

2 matching column graphs on separate tabs, 1 tab for hospitalisations and 1 for deaths. The columns represent sex within 6 life-stage age groups. For each age group, the reader can choose to display either rate per 100,000 population or number. The default displays males and females and the reader can also choose 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. Some of the ways to measure the severity of hospitalised injuries are:

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

The average number of days in hospital for injuries in this category was below the average for all hospitalised injuries, but the percentage of hospitalisations that included time in an ICU or involved continuous ventilatory support were much higher than for all hospitalised injuries in 2020–21. Rates of in-hospital death were about average (Table 3).

Table 3: Severity of injuries of undetermined intent that led to hospitalisation, 2020–21
 

Undetermined intent

All injuries

Average number of days in hospital

2.5

4.4

% of cases with time in an ICU

10.4

2.2

% of cases involving continous ventilatory support

9.0

1.2

In-hospital deaths (per 1,000 cases)

5.3

5.3

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.

For more detail, see Data tables A13–15.

Aboriginal and Torres Strait Islander people

Among Aboriginal and Torres Strait Islander people:

  • there were 394 hospitalisations of undetermined intent in 2020–21 (Table 4)
  • males had higher rates of hospitalisation
  • hospitalisation rates were highest among people aged 25–44, compared with other life stage age groups (Figure 4)
  • there were 14 deaths of undetermined intent in 2019–20 (Table 5).
Table 4: Hospitalisations for injuries of undetermined intent by sex, Indigenous Australians, 2020–21

 

Males

Females

Persons

Number

232

162

394

Rate (per 100,000)

54

38

 46

Note: Rates are crude per 100,000 population.

Source: AIHW National Hospital Morbidity Database.

Table 5: Deaths from injuries 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 2020–21, Indigenous Australians were 3.5 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 injuries of undetermined intent by Indigenous status and sex, 2020–21 hospitalisations

 

Males

Females

Persons

Indigenous Australians

59

 40

 50

Non-Indigenous Australians

16

12

14

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 rate of injury hospitalisations 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 4).

Deaths data are not presented because of small numbers.

Figure 4: Hospitalisations for injuries of undetermined intent, by Indigenous status, by age group and sex, 2020–21

Column graph representing data for Indigenous and non-Indigenous Australians by 6 life-stage age groups. The reader can choose to display rate per 100,000 population or number. By default, data for persons is displayed, the reader can also choose to display males or females.

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

Remoteness

In 2020–21, people living in Very remote areas, compared with people living in Major cities, were 1.8 times as likely to be hospitalised due to injuries of undetermined intent (Table 7).

Table 7: Age-standardised rates (per 100,000) of hospitalisation for injuries of undetermined intent by remoteness and sex, 2020–21
 

 Males

 Females

 Persons

Major cities

               17

               12

               14

Inner regional

               20

               14

               17

Outer regional

               17

               14

               16

Remote

               24

               17

               21

Very remote

               33

 n.p.

               25

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

Source: AIHW National Hospital Morbidity Database.

The highest rate of hospitalisations for injuries of undetermined intent was among the 15–24 age group living in Remote areas of Australia (Figure 5).

Deaths data are not presented here because of small numbers.

Figure 5: Hospitalisations for injuries of undetermined intent, by remoteness, by age group and sex, 2020–21

Column graph representing data for each of the 5 remoteness categories by 6 life-stage age groups. The reader can choose to display rate per 100,000 population or number. By default, the graph displays data for persons. The reader can also choose to display data for males or females.

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

For information on how the statistics were calculated by remoteness, see the technical notes.

Data details

Technical notes: how the data were calculated

Data tables: download the full tables

Glossary