Health-related factors predict return to custody in a large cohort of ex-prisoners: new approaches to predicting re-incarceration

Abstract

Background Numerous poor health outcomes have been documented in the world’s large and growing population of prisoners and ex-prisoners. Repeat justice involvement and incarceration is normative for ex-prisoners in most countries. This study aimed to identify important health-related predictors of re-incarceration and to quantify their contribution to predicting re-incarceration. Methods Participants were 1 325 adult ex-prisoners in Queensland, Australia. We developed a multivariate Cox proportional hazards model for re-incarceration including health-related covariates from a pre-release survey. Results In addition to well-established risk factors (criminal history, drug-related sentence, younger age, male gender and Indigenous ethnicity), several health-related variables were important risk factors for re-incarceration in multivariate analyses, including risky use of cannabis (hazard ratio 1.27; 95% confidence interval 1.06, 1.51), amphetamines (HR 1.20; 95%CI 0.99, 1.46) or opioids (HR 1.33; 95%CI 1.08, 1.63) prior to incarceration, central nervous system medication prescription (HR 1.28; 95%CI 1.06, 1.54), reporting that maintaining physical health post-release was not important (HR 1.52; 95%CI 0.98, 2.36) and poverty prior to incarceration (HR 1.24; 95%CI 1.02, 1.52). Sedentary behaviour (HR 0.82; 95%CI 0.68, 1.00), obesity (HR 0.81; 95%CI 0.64, 1.02), multiple lifetime chronic illnesses (HR 0.85; 95%CI 0.71, 1.01) and a history of self-harm (HR 0.72; 95%CI 0.59, 0.88) were associated with a reduced risk of re-incarceration. Inclusion of health-related variables in the model improved prediction of re-incarceration compared to a model with only demographic and criminal justice predictors, leading to an increase in adjusted proportion of explained variation of 0.051 (95%CI 0.031, 0.107). Conclusions Health-related factors predict re-incarceration after adjustment for demographic and criminal justice factors. Further research is required to establish the reproducibility of our findings and understand the causal pathways linking health at release from prison to re-incarceration.