Met and unmet prison-based treatment needs for people who are incarcerated with a history of substance use disorder: A nationwide cohort study

Background: Substance use disorders (SUD) are highly prevalent among incarcerated people. However, in some prisons, only a small percentage of those who need treatment receive it. The aims of this study were to examine coverage of treatment for SUD in Danish prisons and assess whether treatment differed by substance class. Further, we examined factors associated with receiving treatment for SUD, and types of services received.Data and methods: We linked multiple Danish register data using unique personal identification numbers. This study retrospectively analysed data for 49,330 individuals (aged 18-90) incarcerated in Danish prisons between 2008 and 2018. We used a multivariable logistic regression model to predict enrolment in treatment for SUD in prison.Results: Of incarcerated people with a history of SUD, 34.6 % received treatment care during incarceration. We observed only minor variations in terms of substance classes concerning the type of treatment. Those who were women, immigrants, had higher education, or were married were less likely to receive treatment. Conclusions: Improving access and increasing treatment coverage in the Danish Prison and Probation Services is crucial to reduce the burden of SUD in incarcerated populations.