Re-incarceration and associated social, structural and behavioural factors among people who use drugs in an urban Canadian setting.

Abstract

People who use drugs (PWUD) are disproportionately incarcerated, however little is known about specific substance use, social and structural factors associated with re-incarceration among PWUD. We aimed to identify the socio-structural and substance use factors associated with re-incarceration among structurally-marginalized PWUD. We used longitudinal data from two prospective cohorts of PWUD in Vancouver, Canada. We included adults reporting at least one incarceration event in the last six months and who completed at least one additional follow-up study visit. We performed multivariable extended Cox regression to explore factors associated with re-incarceration. Among 468 eligible participants, the median age was 40 years (Q1-Q3=34-46 years), 346 (73.9%) were men, 177 (37.8%) identified as Indigenous, and 227 (48.5%) experienced at least one re-incarceration event. Incidence rate of re-incarceration was 157 incarceration events per 1000 person years. In multivariable analyses, homelessness (adjusted hazard ratio [AHR]=2.17; 95% confidence interval [95% CI]: 1.79-2.61), community judicial supervision (AHR=3.89; 95% CI: 3.21-4.71) and re-incarceration during the study period (once: AHR=1.95, 95% CI: 1.55-2.44; two or more events: AHR=1.53, 95% CI: 1.23-1.90) were positively associated with re-incarceration. Among substance use variables that included illicit drugs, only heavy alcohol use remained significantly associated with re-incarceration across analyses after adjustment (AHR=1.32; 95% CI: 1.06-1.65). Engagement in addiction treatment (AHR=0.63; 95% CI: 0.53-0.75), mental illness (AHR=0.70; 95% CI: 0.59-0.84) and age (AHR=0.96; 95% CI: 0.95-0.97) were negatively associated with re-incarceration. Access to housing and substance use services, including treatment for alcohol use disorder, following incarceration may reduce re-incarceration among PWUD. The high rates of re-incarceration of PWUD in our sample underscores how structural factors-such as homelessness and criminalization of substance use-drive re-incarceration among PWUD.