Opioid agonist treatment uptake within provincial correctional facilities in British Columbia, Canada

Background and Aims Multiple interventions and policy changes related to opioid agonist treatment (OAT) have been introduced in British Columbia, Canada to increase engagement and retention in OAT. We aimed to estimate the impact of policy changes and the announcement of the opioid overdose-related public health emergency on the use of OAT for incarcerated individuals with opioid use disorder. Design Interrupted time-series analysis. Events of interest included the expansion of buprenorphine/naloxone into provincial health-care insurance coverage in October 2015 and the public health emergency declared in April 2016. Setting and Participants Our study included 9220 incarcerated individuals from 12 provincial corrections facilities in British Columbia, Canada for a total of 75 649 calendar months of incarceration. Measurements Monthly measures of OAT use during incarceration from 1 January 2013 to 30 September 2017. We estimated changes in OAT use, controlling for individual and facility-level factors, using a general estimating equation, specified with a logit link and an autoregressive correlation matrix. Findings After the provincial health insurance coverage expansion, a sharp increase in OAT use during incarceration was observed [adjusted odds ratio (aOR) = 1.16, 95% confidence interval (CI) = 1.13, 1.19]. The public health emergency coincided with an immediate but temporary increase in OAT receipt (aOR = 1.34, 95% CI = 1.22, 1.47). During the entire study period, we estimated a 10-fold increase in the adjusted odds of OAT use during incarceration (aOR = 10.10, 95% CI = 8.98, 11.37). Conclusion Following an expansion of health-care insurance coverage to include buprenorphine/naloxone, receipt of opioid agonist treatment (OAT) within correctional facilities in British Columbia, Canada increased, largely driven by an increase in buprenorphine/naloxone prescriptions among individuals without recent OAT experience.