There are many ways the severity, or seriousness, of an injury can be measured. Severity metrics in this report are used to compare child age groups to each other, and adults.

Triage category: Every ED presentation is assigned 1 of 5 triage categories based on the urgency with which the patient requires medical care.

Seen on time: Each triage category has a clinically appropriate waiting time cut-off between the patient being triaged and seen for medical assessment. A patient is seen on time if they receive care within this timeframe.

End status: A person can leave the ED in different ways. People admitted to hospital are likely to have more serious injuries.

Emergency admission: Urgency of admission reflects the severity of injury or health episode/event. Emergency admissions require admission within 24 hours.

Same day discharge: When a patient is discharged on the same day as they were admitted, this is flagged as a same day discharge. 

ICU: Intensive Care Units (ICUs) provide care to patients who are critically unwell and require complex, multisystem life support.

CVS: Continuous Ventilatory Support (CVS) is when a patient breathes via an artificial airway with the aid of a machine.

Length of stay: The number of days a patient remains in hospital receiving treatment.

In-hospital deaths: When a person is admitted to hospital, and dies despite the treatment provided, that can be an indication of the severity of their injuries.

A greater proportion of children are seen on time compared to adults

73% of injury ED presentations were seen on time for children and adolescents, compared to 69% for adults (Table 4). Children aged 5–9 and 10–12 had the highest proportion of cases seen on time (75%).

This could be explained by the differences in triage categories between children and adults. Triage categories have clinically appropriate waiting time cut-offs based on their severity. More serious ED presentations have a shorter window of time for a patient to be seen on time. Adults tend to have a greater proportion of cases that are assigned higher triage categories compared to children; 2 in 5 adults had a triage category of urgent or above (41%), compared to 1 in 3 children (32%). 

Infants aged less than 1 had the highest proportion of emergency (15%) and urgent cases (41%) of any children’s age group.

Table 4: Proportion of emergency department presentations seen on time, by triage category and population group, 2020–21
Triage categoryClinically appropriate waiting time cut-off    Percent of children assigned category (%)   Percent of children seen on time (%)    Percent of adults assigned category (%)   Percent of adults seen on time (%)


Immediate (within seconds)0.4991.1100


Within 10 minutes7.4 7211 67


Within 30 minutes 2565 3061


Within 60 minutes 5774 48 71


Within 120 minutes 11 8511 83



Children are less likely than adults to be admitted to hospital after presenting to an emergency department

Fewer than 1 in 10 children who present to an ED for an injury go on to be admitted to hospital (9%), compared to 1 in 5 adults (22%). Among children, infants aged under 1 had the highest proportion of cases admitted to hospital (13%).

Injury hospitalisations for children are generally less severe than for adults

When comparing all children with adults, adult injury hospitalisations are more severe across all 6 severity metrics. The only exception is for children aged between 0–9, who experience a higher proportion of emergency admissions.

Table 5: Proportion of emergency department presentations seen on time, by triage category and population group, 2020–21
Severity metricUnder 11–45–910–12  13–1516–18All childrenAdults
Percentage of emergency admissions (%) 9482817976727879
Percentage of same day discharges (%)536355 5247 495438
Percentage in ICU (%)0.9 0.6 0.50.6 1.12.0 1.0 2.2
Percentage on CVS (%) 0.5 0.40.2 0.4 0.5 1.4 0.6 1.2
Length of stay (days)  1.8  1.4     1.3  1.5   1.6  1.8  1.53.8
In-hospital deaths (per 1000 cases)n.p.   n.p.n.p.n.p.n.p.n.p. 0.6 7.0

Thermal causes require the greatest length of stay in hospital

Overall, children spend a shorter period of time in hospital compared to adults, with 1.5 days on average compared to nearly 4 for adults. Some causes of injury have higher average lengths of stays, with injuries caused by thermal causes such as burns spending the longest time in hospital (2.9 days) (Figure 16).

Figure 16: Average length of stay (days) for injury hospitalisations among children and adolescents, by sex, Australia, 2021–22

Average length of stay in hospital by external cause group and sex. Thermal causes have the longest average length of stay.


1.    Length of stay calculations include transfer hospitalisations.

2.    Only includes records where the patient was between 0 and 18 years of age.

3.    Excludes causes with low numbers of hospitalisation due to data volatility.

Source: AIHW National Hospital Morbidity Database (NHMD)

For more information, see supplementary data table A18.