The effect of British Columbia's Pharmacare coverage expansion for opioid agonist treatment.

Opioid agonist treatment (OAT) is the evidence-based standard of care for people with opioid use disorder. In British Columbia, Canada, only social assistance registrants received full coverage for OAT prior to the introduction of the Pharmacare Plan G coverage expansion on February 1st, 2017. We aimed to determine the effect of the coverage expansion on OAT initiation, re-initiation, and retention. Using linked population-level data, we executed a difference-in-differences analysis to compare outcomes of individuals eligible for the additional coverage and social assistance registrants already receiving the most generous coverage for OAT prior to the policy change, adjusting for individual and prescriber characteristics. We found Plan G coverage expansion significantly increased OAT retention. Specifically, coverage expansion decreased the number of OAT episode discontinuations by 12.8% (95% CI: 8.4%, 17.2%).

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.

The effect of a methadone reformulation on opioid agonist treatment outcomes: A population-based study in British Columbia, Canada, 2013-14.

INTRODUCTION: The province of British Columbia, Canada, changed the existing oral anhydrous methadone solution to a 10-times more concentrated pre-mixed solution, Methadose®, on February 1, 2014. We aimed to assess the immediate effects of the methadone reformulation on missed doses, days off methadone, changes in medication dosing and dispensations of opioids for pain, and hospitalizations and mortality among all people receiving treatment at or near the time of the change. METHODS: We conducted a population-based retrospective cohort study including all individuals receiving at least one methadone dispensation in the 12 months prior to the study period. We executed a difference-in-differences analysis by estimating a multivariate regression model to compare outcomes in the three months before and after the reformulation (November 1, 2013 to April 30, 2014) versus a time-lagged control cohort with similar characteristics observed during an equivalent nonoverlapping interval. We used daily individual-level linked health administrative data capturing missed doses, days off methadone, changes in methadone dosing, concurrent dispensations of opioids for pain, hospitalizations, and mortality. We stratified the cohorts into three subgroups: (i) those receiving OAT for ≥12 months; (ii) those receiving OAT for <12 months; and (iii) those not receiving OAT at the start of the study period. We conducted sensitivity analyses and placebo tests to assess the robustness of our results. RESULTS: Among the 16,339 individuals receiving methadone during the study period, the reformulation was associated with more instances of methadone dose increases (34.5% [95% Confidence Interval (CI): 27.4%, 41.5%]). For those retained in treatment ≥12 months prior to the study period (n = 7449), the reformulation was associated with more instances of methadone dose increases (50.2% [39.5%, 60.8%]) and dispensations of opioids for pain (62.2% [40.8%, 83.5%]), as well as an increase in missed doses (41.9% [29.1%, 54.7%]) and days off methadone (62.6% [39.7%, 85.4%]). We found no statistically significant change in risk of hospitalization or mortality. Sensitivity analyses supported our results. CONCLUSION: Our results reinforce the need expressed by people receiving methadone for greater client involvement in the planning and implementation of regulatory changes that may impact client care, especially those patients with a relatively long treatment history.

Evaluation of risk mitigation measures for people with substance use disorders to address the dual public health crises of COVID-19 and overdose in British Columbia: a mixed-method study protocol.

INTRODUCTION: The COVID-19 pandemic was preceded by an ongoing overdose crisis and linked to escalating drug overdose deaths in British Columbia (BC). At the outset of these dual public health emergencies, the BC government announced interim Risk Mitigation Guidance (RMG) that permitted prescribing medication alternatives to substances, including opioids, alcohol, stimulants and benzodiazepines, an intervention sometimes referred to as 'safe supply'. This protocol outlines the approach for a study of the implementation of RMG and its impacts on COVID-19 infection, drug-related and systemic harms, continuity of care for people with substance use disorder (SUD), as well as their behavioural, psychosocial and well-being outcomes. METHODS AND ANALYSIS: We conducted a parallel mixed-method study that involved both analysis of population-level administrative health data and primary data collection, including a 10-week longitudinal observational study (target n=200), a cross-sectional survey (target n=200) and qualitative interviews (target n=60). We implemented a participatory approach to this evaluation, partnering with people with lived or living expertise of drug use, and researchers and public health decision-makers across the province. Linked population-level administrative databases will analyse data from a cohort of BC residents with an indication of SUD between 1996 and 2020. We will execute high-dimensional propensity score matching and marginal structural modelling to construct a control group and to assess the impact of RMG dispensation receipt on a collaboratively determined set of primary and secondary outcomes. ETHICS AND DISSEMINATION: Study activities were developed to adhere to the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans, recommended COVID-19 research practices, and guided by the Truth and Reconciliation Commission's Calls to Action for public health, data governance and research ethics related to Indigenous people. Results will be disseminated incrementally, on an ongoing basis, through the consortium established for this study, then published in peer-reviewed journals.

The cascade of care for opioid use disorder: a retrospective study in British Columbia, Canada.

BACKGROUND AND AIMS: The 'cascade of care' framework, measuring attrition at various stages of care engagement, has been proposed to guide the public health response to the opioid overdose public health emergency in British Columbia, Canada. We estimated the cascade of care for opioid use disorder and identified factors associated with care engagement for people with opioid use disorder (PWOUD) provincially. DESIGN: Retrospective study using a provincial-level linkage of four health administrative databases. SETTING AND PARTICIPANTS: All PWOUD in BC from 1 January 1996 to 30 November 2017. MEASUREMENTS: The eight-stage cascade of care included diagnosed PWOUD, ever on opioid agonist treatment (OAT), recently on OAT, currently on OAT and retained on OAT: ≥ 1, ≥ 3, ≥ 12 and ≥ 24 months). Health-care use, homelessness and other demographics were obtained from physician billing records, hospitalizations, and drug dispensation records. Receipt of income assistance was indicated by enrollment in Pharmacare Plan C. FINDINGS: A total of 55 470 diagnosed PWOUD were alive at end of follow-up. As of 2017, a majority of the population (n = 39 456; 71%) received OAT during follow-up; however, only 33% (n = 18 519) were currently engaged in treatment and 16% (n = 8960) had been retained for at least 1 year. Compared with those never on OAT, those currently engaged in OAT were more likely to be aged under 45 years [adjusted odds ratio (aOR) = 1.75, 95% confidence interval (CI) = 1.64, 1.89], male (aOR = 1.72, 95% CI = 1.64, 1.82), with concurrent substance use disorders (aOR = 2.56, 95% CI = 2.44, 2.70), hepatitis C virus (HCV) (aOR = 1.22, 95% CI = 1.14, 1.33) and either homeless or receiving income-assistance (aOR = 4.35, 95% CI = 4.17, 4.55). Regular contact with the health-care system-either in out-patient or acute care settings-was common among PWOUD not engaged in OAT, regardless of time since diagnosis or treatment discontinuation. CONCLUSIONS: People with opioid use disorder in British Columbia, Canada show high levels of out-patient care prior to diagnosis. Younger age, male sex, urban residence, lower income level and homelessness appear to be independently associated with increased opioid agonist treatment engagement.

Comparative effectiveness of buprenorphine-naloxone versus methadone for treatment of opioid use disorder: a population-based observational study protocol in British Columbia, Canada.

INTRODUCTION: Despite a recent meta-analysis including 31 randomised controlled trials comparing methadone and buprenorphine for the treatment of opioid use disorder, important knowledge gaps remain regarding the long-term effectiveness of different treatment modalities across individuals, including rigorously collected data on retention rates and other treatment outcomes. Evidence from real-world data represents a valuable opportunity to improve personalised treatment and patient-centred guidelines for vulnerable populations and inform strategies to reduce opioid-related mortality. Our objective is to determine the comparative effectiveness of methadone versus buprenorphine/naloxone, both overall and within key populations, in a setting where both medications are simultaneously available in office-based practices and specialised clinics. METHODS AND ANALYSIS: We propose a retrospective cohort study of all adults living in British Columbia receiving opioid agonist treatment (OAT) with methadone or buprenorphine/naloxone between 1 January 2008 and 30 September 2018. The study will draw on seven linked population-level administrative databases. The primary outcomes include retention in OAT and all-cause mortality. We will determine the effectiveness of buprenorphine/naloxone vs methadone using intention-to-treat and per-protocol analyses-the former emulating flexible-dose trials and the latter focusing on the comparison of the two medication regimens offered at the optimal dose. Sensitivity analyses will be used to assess the robustness of results to heterogeneity in the patient population and threats to internal validity. ETHICS AND DISSEMINATION: The protocol, cohort creation and analysis plan have been approved and classified as a quality improvement initiative exempt from ethical review (Providence Health Care Research Institute and the Simon Fraser University Office of Research Ethics). Dissemination is planned via conferences and publications, and through direct engagement and collaboration with entities that issue clinical guidelines, such as professional medical societies and public health organisations.