Fatal and nonfatal opioid overdose risk following release from prison: A retrospective cohort study using linked administrative data.

Introduction: Among individuals who are released from prison, opioid overdose is a leading cause of death with a risk more than ten-fold the general population. Although the epidemiology of opioid-related fatalities has been described, few studies have characterized both fatal and nonfatal opioid-related poisonings. The objective of this study was to estimate risk of fatal and nonfatal opioid overdose among adults released from prison.

Methods: The study estimated fatal and nonfatal opioid overdose rates using linked corrections, Medicaid, hospital discharge, and vital statistics from the state of Oregon from 2014 to 2018. Multivariable proportional hazards models identified demographic and prison-related factors associated with overdose.

Results: Between 2014 and 2017, 18,258 individuals were released from prison. A majority of individuals were male (87 %) and ages 26 to 64 (83 %). Two-thirds had a documented substance use disorder treatment need and 20 % demonstrated mental health treatment need. Following prison release, 579 opioid overdose events occurred; 65 (11 %) were fatal. The rate of opioid overdose was 1085.7 per 100,000 person-years (PY). Rates were highest in the first two weeks (2286.7 per 100,000 PY), among women (1582.9 per 100,000 PY), and those with mental health (1624.3 per 100,000 PY) or substance use disorder treatment needs (1382.6 per 100,100 PY). Only mental health (adjusted hazard ratio [aHR] 1.54, 95 % CI 1.24 to 1.90) and substance use need (aHR 2.59; 95 % CI 2.01 to 3.34) remained significant in multivariable models.

Conclusions: The rate of opioid overdose is markedly elevated after prison release, particularly in the first two weeks. In women, the higher rate of opioid overdose is mediated by a greater mental health burden.