Violence-related morbidity among people released from prison in Australia: A data linkage study

Introduction People released from prison have an increased risk of morbidity, including from nonfatal violence. We examined the incidence and predictors of violence-related morbidity after release from prison and investigated whether there are differences according to sex and Indigenous status. Methods Baseline data were collected from 1325 people within 6 weeks of release from prisons in Queensland, Australia, between 1 August 2008 and 31 July 2010. Data were linked to state-wide health (ambulance, emergency department and hospital) and prison records, and national death records until 31 July 2012. Predictors were identified using a multivariable Andersen-Gill model. Differences according to sex and Indigenous status were investigated using effect modification. Results A total of 225 (18.2%) people experienced 410 violence-related events that were recorded in health records. The incidence was 12.8 per 100 person-years [95% confidence interval (CI) 11.7, 14.1]. Risk factors for violence-related morbidity included diagnosed mental illness [hazard ratio (HR) = 2.0, 95% CI 1.1, 3.8], substance use disorder (HR = 1.6, 95% CI 1.1, 2.3) or dual diagnosis (HR = 3.2, 95% CI 2.2, 4.8); high-risk alcohol use (HR = 2.1, 95% CI 1.5, 2.8); being Indigenous (HR = 1.7, 95% CI 1.2, 2.5); and two or more prison releases (HR = 1.7, 95% CI 1.2, 2.6). Indigenous status modified the risk of violence-related morbidity, with Indigenous men having twice the risk of non-Indigenous men (HR = 1.9, 95% CI 1.3, 2.8). Discussion and Conclusions Approximately one in five people released from prisons in Queensland experienced violence-related morbidity. Coordinated and continuous mental health and substance use treatment from prison to the community may reduce the risk of violence-related morbidity in this population.