Exploring the impact of criminal justice contact on mortality among individuals engaging in drug treatment in Scotland (2012–2015): a retrospective cohort study using linked administrative data

McGhee, John (2026) Exploring the impact of criminal justice contact on mortality among individuals engaging in drug treatment in Scotland (2012–2015): a retrospective cohort study using linked administrative data. PhD thesis, University of Glasgow.

Abstract

Scotland continues to experience exceptionally high rates of drug-related harm, disproportionately affecting people facing multiple, overlapping health and social vulnerabilities. Many of these vulnerabilities are closely linked to contact with the criminal justice system (CJS), yet there remain persistent limitations in how this contact is recorded and understood in drug treatment and mortality data. This thesis addresses these gaps by analysing linked administrative data from the Scottish Drug Misuse Database (SDMD) and National Records of Scotland (NRS) mortality records. The study includes all individuals who entered Tier 3 or Tier 4 drug treatment services in Scotland between 2012 and 2015, with mortality follow-up to the end of 2020, comprising a cohort of 35,331 individuals and 4,008 deaths.

The thesis is guided by eight research questions and structured into three empirical chapters. Chapter 3 reconceptualises the measurement of CJS contact, showing that standard recording practices substantially underestimate the extent of justice involvement among the treatment population. Using a broader set of indicators, the analysis shows that over half (52.6%) of individuals in treatment had some form of CJS contact. Chapter 4 examines how demographic characteristics, substance use patterns, health status, and social conditions vary across three CJS categories: no contact, non-prison contact, and prison experience. Chapter 5 investigates mortality within the cohort and assesses the factors associated with death, including whether these associations differ across CJS groups.

The analysis combines descriptive statistics, chi-squared and Kruskal–Wallis tests, and regression modelling to examine associations between mortality and a range of demographic, health, substance use, and social variables. The findings show that individuals with different forms of CJS contact exhibit distinct profiles of risk and vulnerability, particularly among those with a history of imprisonment. However, after adjustment for these factors, CJS contact was not independently associated with mortality. Instead, mortality was associated with a combination of high-risk drug use (including injecting and benzodiazepine use), health-related need, and markers of social and structural disadvantage, such as unstable housing and limited employment engagement. These factors were unevenly distributed across CJS groups, shaping distinct risk profiles.

The findings suggest that mortality among people in drug treatment is best understood as the outcome of intersecting health, social, and structural conditions, rather than as a consequence of criminal justice contact in isolation. The thesis concludes that reducing preventable deaths in this population requires more integrated, public health-oriented responses that address these underlying determinants, alongside improvements in how justice involvement is recorded and understood in administrative data.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: H Social Sciences > HN Social history and conditions. Social problems. Social reform
• Colleges/Schools: College of Social Sciences > School of Social and Political Sciences
• Supervisor's Name: Armstrong, Professor Sarah and McVie, Professor Susan
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-86072
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 25 Jun 2026 10:01
• Last Modified: 26 Jun 2026 08:06
• Thesis DOI: 10.5525/gla.thesis.86072
• URI: https://theses.gla.ac.uk/id/eprint/86072