Summary

Generally, people living in lower socioeconomic groups are at greater risk of poor health; have greater rates of illness, disability and death; and live shorter lives than people from higher socioeconomic groups. The better a person’s social and economic circumstances, the healthier they tend to be; this is often called the ‘social gradient of health’. Injury is a leading cause of illness, disability and premature death in Australia, and a person’s socioeconomic circumstances are an important determinant of injury. However, the relationship between injury and socioeconomic factors has been shown to vary. Little research on this has been undertaken in Australia and only a small number of international studies and reviews have been published.

This report examines the effects of socioeconomic status (SES) on injury deaths in Australia in 2015–16. It looks at the effects of SES on injury deaths by age and sex and by a selection of external causes of injury. It also looks at the effects of socioeconomic factors over time by comparing cases from the most disadvantaged and least disadvantaged socioeconomic groups. It finds that, overall, rates of injury death were higher among people from the lowest (most disadvantaged) socioeconomic group than among people from the highest (least disadvantaged) group. This was most evident for Transport crash deaths, Unintentional poisoning deaths and male Suicide deaths. However, there was little evidence of such an association for Unintentional fall injury deaths and for females in relation to Unintentional drowning deaths, Unintentional thermal injury deaths or suicide deaths.

For external causes of injury where a strong association between increasing socioeconomic disadvantage and the likelihood of injury was apparent, there was variability across age groups. For example, for Unintentional poisoning deaths, the association between increasing socioeconomic disadvantage and the likelihood of injury was strongest in those aged 25–44 and 45–64, but not as evident in other age groups. For Suicide deaths, this association was strongest in those aged 25–44, while an opposite (but a weaker) effect was observed for those aged 65 and over. Patterns were difficult to interpret for Drowning and Thermal injury deaths, due to relatively low case counts across most age groups.

Variations were also seen when the proportion of deaths by SES was examined by age group. For most external causes, there were generally larger proportions of cases within the 2 most disadvantaged groups in each age group. An exception was for Thermal injury deaths, where the highest proportion of deaths occurred in the more advantaged groups for those aged 15–24 and 25–44—although this result should be interpreted with caution, due to relatively low case numbers. The effect was strongest among Homicide deaths where the proportion of deaths in the lowest (most disadvantaged) socioeconomic group was pronounced in those aged 15–24, 25–44 and 45–64 but not so in those aged 65 and over.

Trends over time

Over the period from 2009–10 to 2015–16, the rate of injury deaths increased for the lowest (most disadvantaged) socioeconomic group by 1.1% per year, while little change was observed for the highest (least disadvantaged) group (Table A1). For the most disadvantaged group, the only other statistically significant increases over time were for Unintentional poisoning deaths (5.4% per year) and Suicide deaths (3.5% per year); for the least disadvantaged group, the only statistically significant increase was for Unintentional falls deaths (2.5% per year).

Transport crashes was the only external cause group to record significant decreases in rates of injury deaths over time for both the most disadvantaged group (2.6% per year) and the least disadvantaged group (3.7% per year). For all other external causes, there were no significant changes in rates over time in either of the socioeconomic groups—apart from Drowning, where rates fell by 4.7% per year in the most disadvantaged group.

Table S1: Summary of trends over time for selected external causes, by 2 categories of socioeconomic status of area of usual residence, Australia, 2009–10 to 2015–16

 

External cause

Lowest socioeconomic group
(Most disadvantaged)
Direction of trend
Lowest socioeconomic group
(Most disadvantaged)
Percentage change
per year
Highest socioeconomic group
(Least disadvantaged)
Direction of trend
Highest socioeconomic group
(Least disadvantaged)
Percentage change per year
All injury

1.1

(a)

0.1

Transport crash 2.6 3.7
Drowning 4.7 (a) (3.7)(b)
Unintentional poisoning 5.4 (a) (1.5)(b)
Falls (a) 1.2 2.5
Thermal causes (a) 5.1 (b) (a) (9.8)(b)
Suicide 3.5 (a) 0.2
Homicide (a) 1.1 (a) (6.4) (b)

Notes:

  1. Average percentage change per year did not differ significantly from zero (p ≥ 0.05).

  2. Average percentage change per year was negative but did not differ significantly from zero.

Changes in rates over time by socioeconomic group, external cause and age group varied considerably. Between 2009–10 and 2015–16, rates for Transport crash deaths and Drowning deaths decreased for nearly all age groups, for both the most disadvantaged and the least disadvantaged socioeconomic groups. However, only the decrease in rates for Transport crash deaths for those aged 15–24 and 25–44 in the most disadvantaged group and for those aged 25–44 in the least disadvantaged group were statistically significant.

Rates for the 2 oldest age groups in Unintentional fall injury deaths and nearly all of the 4 oldest age groups in suicide deaths increased over the period of interest. However, the only statistically significant increase in Suicide deaths rates occurred for those aged 25–44 in the most disadvantaged group. Rates for Unintentional poisoning deaths for those aged 15–24 decreased over the period of interest in both socioeconomic groups (although the decrease was statistically significant only for the least disadvantaged group). Rates for those aged 25–44, 45–64 and 65 and over all increased over time in the most disadvantaged group, while there was little change in these 3 age groups in the least disadvantaged group.