**3. Results**

Across the study period, there were a total of 5153 children who died due to fatal injuries. As a rate per 100,000 population, injury-related mortality among 0–19-year-olds in Australia varied from a high of 10.80 in 2008-09 to a low of 7.26 in 2013–14. The temporal trend across the study period shows a decline (y = −0.3166x + 10.627; R<sup>2</sup> = 0.72) (Figure 1).

**Figure 1.** Crude rate per 100,000 of injury-related fatalities among children and adolescents 0–19 years, Australia 2007-08 to 2016-17.

The highest rates of fatal injury were seen in the 15–19 years age group with an average rate across the study period of 22.23 per 100,000, compared with the lowest rate of 2.63 per 100,000 among the 5–9 years age group. Crude injury-fatality rates are declining among 15–19-year-olds, with stagnant rates among 0–4-year-olds and 5–9-year-olds, with a slight upturn in rates among 10–14-year-olds (Figure 2).

Males accounted for 67.7% of all fatalities (*n* = 3487). Males were overrepresented in all age groups, rising from 59.1% of all injury-related fatalities in the 0–4 years age group, to 71.8% of all fatalities in the 15–19 years age group.

**Figure 2.** Crude rate per 100,000 of injury-related fatalities among children and adolescents 0–19 years, Australia 2007-08 to 2016-17.

Road traffic and other land transport incidents was the leading injury mechanism, accounting for 38.2% (*n* = 1970) of the overall injury-related fatality burden, followed by intentional self-harm (*n* = 1432; 27.8%) and drowning (*n* = 419; 8.1%). The overrepresentation of males was most pronounced in injury-related fatalities as a result of falls (82.6% male) and electrocution, radiation and extreme temperatures (80.0% male). When calculated as crude fatality rates, road traffic and other land transport incidents recorded a fatality

rate of 3.39 per 100,000 population, compared to 2.46 for intentional self-harm and 0.72/100,000 population for drowning (Table 2).


**Table 2.** Incidence of injury-related fatality by mechanism, proportion of total and crude rate per 100,000 population among children and adolescents 0–19 years of age, Australia, 2007-08–2016-17.

### *3.1. Impact of Social Determinants on Injury-Related Fatalities—Remoteness Classification*

The rate of injury-related fatalities increased as remoteness increased. Major cities record a crude rate of 6.64 injury-related fatalities per 100,000 residents; rising to a rate of 38.90 per 100,000 residents in very remote areas. Very remote areas recorded injury-related fatalities at six times (RR = 5.84; CI: 3.76–9.12) the rate of major city residents (Table 3).

**Table 3.** Crude rate of injury-related fatality by remoteness classification, relative risk with 95% confidence interval, children and adolescents 0–19 years of age, Australia, 2007-08–2016-17.


Males recorded higher rates of fatal injury than females across all remoteness classifications, with the highest rates seen in very remote areas (12.52 for males compared to 9.79 for females). When compared to major cities, the relative risk of an injury-related fatality was six higher in very remote areas for males (RR = 5.62; CI: 3.20–9.87) and nine times higher for females (RR = 8.73; CI: 4.23–18.00). Rates of injury-related fatalities were highest for 15–19-year-olds across all remoteness classification, ranging from 17.11 fatalities per 100,000 residents in major cities, to a rate of 102.33 in very remote areas (Table 4).

Across the five remoteness classification categories, road traffic and other land transport incidents (2.45) and intentional self-harm (2.12) recorded the highest rates of fatal injury in areas classified as major cities. This pattern continued across all remoteness classifications, with the exception of very remote areas, where the rate of injury-related fatalities associated with intentional self-harm (16.97) overtook that of road traffic and other land transport (14.39). The highest RR of injury-related fatality was for electrocution, radiation and extreme temperatures, with an 18 times (RR = 18.24; CI: 0.02–18638.89) higher risk of dying from this injury mechanism in a very remote area than in a major city. (Table 5).


**Table 4.** Crude rate of injury-related fatality by remoteness classification, relative risk (RR) with 95% confidence interval (CI), children and adolescents 0–19 years of age, Australia, 2007-08–2016-17.

When compared to females, a proportionately higher number of males in the 0–4 years age group died from road transport and other land transport injuries in major cities (57.1%), rising to 79.3% for the 15–19 years age group in very remote areas. When compared to males, a proportionately higher number of females aged 10–14 years died due to road transport related injuries in very remote areas (62.5%). For intentional self-harm related fatalities, sex differences were most pronounced among 15–19-year-olds in inner regional areas, where males accounted for 73.1% of fatalities. Sex differences for drowning were most pronounced in major cities for the 15–19 years age group, with males accounting for 90.9% of all drowning-related fatalities.


**Table 5.** Crude rate per 100,000 population of injury-related fatality by mechanism and remoteness classification, relative risk (RR) and 95% confidence interval (CI), among children and adolescents 0–19 years of age, Australia, 2007-08–2016-17.

UTBC = Unable to Be Calculated.

### *3.2. Impact of Social Determinants on Injury-Related Fatalities—Socio-Economic Classification*

There was an annual average of 214 injury-related fatalities in areas classified as mid IRSAD decile, followed by 204 fatalities for low IRSAD decile residences. High IRSAD deciles recorded the lowest average, with 97 injury-related fatalities annually. Injury-related fatalities declined in all three IRSAD decile classifications across the study period, with the largest decrease occurring in the mid decile (y = −9.1273x + 264.4; R<sup>2</sup> = 0.6734). (Figure 3).

**Figure 3.** Injury-related fatalities among children and adolescents 0–19 years by index of relative socio-economic advantage and disadvantage (IRSAD) decile, Australia 2007-08 to 2016-17. Note: there were four cases with unknown IRSAD.

The highest proportion of injury-related fatalities occurred in areas classified as being mid IRSAD deciles (41.6%) and among males (67.7%). Males accounted for a higher proportion of injury-related fatalities than females across all IRSAD deciles. A higher proportion of female injury-related fatalities occurred among high IRSAD deciles (20.0%) than males (18.4%), however sex by IRSAD decile did not have a statistically significant impact on injury-related fatalities (X<sup>2</sup> = 1.86; *p* = 0.395). (Table 6)



Note: excludes four cases with unknown IRSAD classification.

Across all age groups, the highest proportion of injury-related fatalities occurred in areas classified as low IRSAD, with the exception of the 15–19 years age group, where the highest proportion occurred in areas classified as mid IRSAD (36.9%). There was a statistically significant difference in injury-related fatalities for age group by IRSAD. Older children (15–19-year-olds) were more likely to die from injury-related incidents in areas classified as high IRSAD, whereas children (0–4 years) were more likely to die from injury-related incidents if residing in low IRSAD areas (X<sup>2</sup> = 28.58; *p* < 0.001) (Table 7).


**Table 7.** Injury-related fatalities by age group and index of relative socio-economic advantage and disadvantage decile (IRSAD), Australia, 2007/08 to 2016/17.

Note: excludes four cases with unknown IRSAD classification. Each subscript letter (a,b) denotes a subset of IRSAD Grouped into Low Mid High categories whose column proportions do not differ significantly from each other at the 0.05 level using the Bonferroni adjustment (i.e., where there are two a's these are not statistically significant, where there is an a and b these are statistically significant).

Road traffic and other land transport was the leading mechanism of injury-related fatalities in areas classified as low IRSAD (38.9%) and mid IRSAD (40.7%). In areas classified as high IRSAD, intentional self-harm accounted for the highest proportion of injury-related deaths (32.4%). Statistically significant differences (X<sup>2</sup> = 69.05; *p* < 0.001) were found for proportion of injury mechanism by IRSAD for road traffic and other land transport (more likely in low and mid IRSAD deciles), accidental poisoning (high IRSAD), and intentional self-harm (low and mid IRSAD) (Table 8).

When exploring sex differences by injury mechanism, age and IRSAD decile, 15–19-year-old males accounted for a significantly higher proportion of drowning-related deaths in low (96.3% male), mid (89.2%) and high (90.9%) IRSAD deciles. Females aged 0–4 years old accounted for 71.4% of burn-related deaths in high IRSAD deciles. A higher proportion of males aged 15–19 years of age died from intentional self-harm in low IRSAD deciles (72.7% male) compared to mid (68.5% male) and high IRSAD deciles (66.1% male).


**Table 8.** Injury-related fatalities by age group and index of relative socio-economic advantage and disadvantage decile (IRSAD), Australia, 2007-08 to 2016-17.

Note: excludes four cases with unknown IRSAD classification. NP = Not Presented. Each subscript letter (a,b) denotes a subset of IRSAD Grouped into Low Mid High categories whose column proportions do not differ significantly from each other at the 0.05 level using the Bonferroni adjustment (i.e., where there are two a's these are not statistically significant, where there is an a and b these are statistically significant).
