This study aimed to ascertain the existence and acuteness of an ‘incarceration gap’ within the Indigenous Australian population. A number of socio-economic, environmental and clinical factors were compared by life-time incarceration status. As expected, disparities were observed across numerous domains, the most pronounced being for educational obtainment, labour force participation and drug/alcohol problems. These three factors have demonstrated associations with justice-involvement for Indigenous populations in prior research [13-15, 28, 34]. They are also universally common risk factors for offending  and often characterise the risk profiles of non-Indigenous prisoners.
Almost half of the ever-incarcerated group in this study had not completed year 10. This rate was lower than the non-Indigenous male Australian population completion rate of 87.9% , but it was also substantially lower than the year 10 completion rate of never-incarcerated Indigenous Australians. Similar findings were obtained for labour force participation. While the never-incarcerated population’s work force status (56%) was trending towards that of the general Australian male population (65%) , only one-quarter of the ever-incarcerated population reported being employed. In addition, more than half of ever-incarcerated individuals reported that they were not in the labour force (for e.g., retired, voluntarily inactive, home duties, disabled, permanently unable to work). The link between lower educational obtainment and unemployment is well documented . Barriers to ongoing employment are often exacerbated for those with a criminal record. Halving the Indigenous/non-Indigenous school attainment and employment gaps are key CTG targets. However, these aspirations - which have demonstrated some progress – must also contend with the substantial disparities observed here within the Indigenous population by incarceration status.
The third major discrepancy by incarceration status was possessing substance use problems over the past 12 months. Almost 30% of ever-incarcerated individuals reported such problems compared to just 7.2% of never-incarcerated individuals. Alcohol and drug abuse are major contributors to Indigenous offending and other problem behaviours [47-48]. For example, a greater proportion of Indigenous prisoners report being affected by substances at the time of their offending compared to non-Indigenous prisoners . In summary, the incarceration gap appears to be widest for the risk factor triad of under-education, unemployment and substance abuse.
A number of other factors distinguished ever-incarcerated individuals from never-incarcerated individuals, though to a lesser extent. Perhaps unsurprisingly, greater proportions of ever-incarcerated individuals distrusted police. It is not uncommon for individuals with repeat justice involvement to have negative attitudes towards law enforcement and the criminal justice system at large, often due to negative experiences and interactions with police. Attitudes towards police were more favourable for never-incarcerated individuals with less than 20% expressing distrust. The latter finding is more aligned with attitudes towards police for the general Australian population . Another difference by incarceration status was the avoidance of situations due to perceived unfair treatment which was more common among the ever-incarcerated. Although there was some difference in experiences of unfair treatment (42% vs. 32%), a broader concern was that large minorities of both ever and never-incarcerated groups reported receiving unfair treatment. These proportions are similar to those found in other international representative surveys of Indigenous peoples ; and point to ongoing experiences of racism in Australian society. Given their higher levels of education and labour force participation, never-incarcerated individuals may possess an enhanced capacity to navigate perceived discriminatory experiences. It is also possible that perceived experiences of unfair treatment may be augmented for those who inhabit multiple disadvantaged or stigmatised sub-groups (i.e., Indigenous x justice-involved; justice-involved x low socio-economic status x Indigenous).
Ever-incarcerated individuals were also more dispersed across urban and remote regions. This contrasted with never-incarcerated individuals who were more concentrated in major urban areas. Reports have detailed that people living in remote and rural regions are more likely to be exposed to violence  and engage in the harmful use of substances . Indigenous Australians are more likely to live in rural and remote areas of the country compared to non-Indigenous Australians . Moreover, study results indicated that almost three-quarters of ever-incarcerated individuals live in Indigenous-only households compared to 50% of never-incarcerated individuals. This finding may be a reflection of rurality and/or socio-economic status. Evidence suggests that mixed Indigenous/non-Indigenous couples are more likely to reside in major urban areas and tend to be economically better-off [4,53,54]. Another notable difference by incarcerated status was mental health factors. Higher proportions of the ever-incarcerated group reported high to very high levels of distress and a life-time mental health diagnosis (35%). Prior research has pointed to the elevated distress levels of Indigenous prisoners [34,37,55], and Australian prisoners in general [56-57]. The proportion of never-incarcerated individuals with a mental illness (22.7%) is in line with Australian male general population estimates (approx. 18%) . Furthermore, findings imply that proportionally, ever-incarcerated individuals have endured more adverse life experiences. An alarming 17.4% reported being removed from their natural family. It is unknown as to the nature or circumstances of these removals. Historically, many Indigenous children were removed from their families through a systematic government policy known as the ‘Stolen Generation’ . In recent decades, reports have detailed the disproportionate rates of Indigenous young people who have been removed from their parents or primary care-givers ostensibly due to a substantiated risk of harm . Rates of child removal are also reportedly higher in rural and remote areas  where ever-incarcerated individuals are more likely to reside. Additionally, 1 in 5 ever-incarcerated individuals reported experiencing physical violence over the past 12 month compared to approximately 1 in 10 never-incarcerated individuals. However, the never-incarcerated rate is still markedly higher than the Australian general population rate . Indigenous people experience violence at twice the rate of non-Indigenous people . High-risk alcohol use, justice-involvement, unemployment and being removed as a child have demonstrated strong associations with violent victimisation [65-65].
Though reaching significance, several factors yielded minor effects. Reported instances of serious illness/disability over the past 12 months were comparable by incarceration status. These findings are perhaps understated given their restriction to instances within the past year. According to official estimates, almost a quarter of Indigenous Australians report living with a disability, which is higher than for non-Indigenous Australians . Access to health services was unexpectedly similar across groups. Three-quarters of both incarcerated and non-incarcerated respondents reported visiting a doctor over the past 12 months. However, the frequency and nature of the visit was unknown. Nonetheless, this finding is within range of the male Australian general population (80%) and the majority of respondents across incarceration status appeared to trust their own doctor. Both groups were also more inclined to trust hospitals, though ever-incarcerated individuals reported marginally higher levels of distrust. A small effect was observed for the variable ‘problems accessing services’ – almost one-third of the incarcerated group reporting this concern compared to just over 20% of the never-incarcerated group. Health service accessibility problems have been linked to local availability, language barriers and long waiting times for Indigenous Australians, issues that are compounded in remote localities . Ex-prisoners generally tend to visit doctors more than the general population due to more complex health needs , which underscores the concern that a notable minority of the ever-incarcerated group report difficulties accessing services.
The majority of respondent’s reported participating in cultural activities over the past year with little difference found by incarceration status. Some evidence has pointed to the protective influence of cultural involvement/connection for Indigenous people in custody [35, 37-38]. However the temporal relationship between cultural participation and imprisonment was unknown for ever-incarcerated individuals. A meaningful relationship between experiences of racism and justice-involvement in Australia has not been established. Finally, family and community agency differed somewhat by incarcerated status. An insignificant distinction was identified at the community level – the majority of both groups reported having little to no say on important community issues. Much has been written on the lack of community consultation when devising policies directed at improving the lives of Indigenous Australians. However, rates of Indigenous participation (i.e., ‘having a say’) in community issues are similar to those reported by the general Australian population . In contrast, a larger effect was identified at the family level. Ever-incarcerated individuals ‘had a say with family and friends on important issues’ with less regularity compared to never-incarcerated individuals. This may be a function of unavailability due to justice-involvement or perhaps a consequence of family estrangement from the offending relative.
The study had a number of limitations. The Australian Bureau of Statistics (ABS) TableBuilder platform permits users to extract cross-tabulations of simple aggregate information. As such, we were not able to conduct multivariate analyses that would allow for the examination of differences between the incarcerated and non-incarcerated group on one variable whilst adjusting for differences on other variables. However, this was not the intention of this analysis, which was to ascertain collective gaps within the Indigenous population. As such, ABS Table Builder was a useful device for cross-tabulating the aggregate data. In order to examine the correlates of imprisonment using multivariate analyses – an exercise we recommend for this sample - de-identified microdata is required. Our analysis did not include females. We believe this warrants specialised exploration as there may be unique differences within the Indigenous female population by incarceration status as compared to males. Moreover, Indigenous women are one of the fastest growing cohorts in Australian prisons . Particular variables (i.e., Doctor visits past 12 months) provide somewhat limited information without a further qualitative understanding of the experiential nature of the episode. For example, it is possible that one group was more likely to experience suboptimal interactions with medical staff compared to the other group. Finally, the year 10 completion rate in the study may be marginally understated given that a small number of 15 and 16 year olds may have still been completing year 10 at the time of the survey.