Validating a screening tool for mental health and substance use risk in an Indigenous prison population

The Indigenous Risk Impact Screen (IRIS) is a validated culturally appropriate and widely used tool in the community for assessing substance use and mental disorder. This research aimed to assess the utility of this tool in an Indigenous prison population.

The study used data collected from a cross-sectional study of mental health among Indigenous inmates in Queensland custodial centres (n = 395, 84% male). Participants were administered a modified version of the IRIS and International Classification of Diseases-10 diagnoses of substance use, depressive and anxiety disorders obtained using the Composite International Diagnostic Interview (CIDI). The concurrent validity of the modified IRIS was assessed against those of the CIDI.

Three hundred and twelve people screened as high risk for a substance use disorder and 179 were high risk for mental problems. There were 73% of males and 88% of females diagnosed with a mental disorder. The IRIS was an effective screener for substance use disorders, with high sensitivity of 94% and low specificity of 33%. The screener was less effective in identifying depression (sensitivity 82%, specificity 59%) and anxiety (sensitivity 68%, specificity 60%).

The IRIS is the first culturally appropriate screening instrument to be validated for the risk of drug and alcohol and mental disorder among Indigenous adults in custody.

This study demonstrated that the IRIS is a valid tool for screening of alcohol and drug use risk among an incarcerated Indigenous population. The IRIS could offer an opportunity to improve the identification, treatment and health outcomes for incarcerated Indigenous adults.