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

Implementation of pharmaceutical alternatives to a toxic drug supply in British Columbia: A mixed methods study

BACKGROUND

North America has been in an unrelenting overdose crisis for almost a decade. British Columbia (BC), Canada declared a public health emergency due to overdoses in 2016. Risk Mitigation Guidance (RMG) for prescribing pharmaceutical opioids, stimulants and benzodiazepine alternatives to the toxic drug supply ("safer supply") was implemented in March 2020 in an attempt to reduce harms of COVID-19 and overdose deaths in BC during dual declared public health emergencies. Our objective was to describe early implementation of RMG among prescribers in BC.

METHODS

We conducted a convergent mixed methods study drawing population-level linked administrative health data and qualitative interviews with 17 prescribers. The Consolidated Framework for Implementation Research (CFIR) informs our work. The study utilized seven linked databases, capturing the characteristics of prescribers for people with substance use disorder to describe the characteristics of those prescribing under the RMG using univariate summary statistics and logistic regression analysis. For the qualitative analysis, we drew on interpretative descriptive methodology to identify barriers and facilitators to implementation.

RESULTS

Analysis of administrative databases demonstrated limited uptake of the intervention outside large urban centres and a highly specific profile of urban prescribers, with larger and more complex caseloads associated with RMG prescribing. Nurse practitioners were three times more likely to prescribe than general practitioners. Qualitatively, the study identified five themes related to the five CFIR domains: 1) RMG is helpful but controversial; 2) Motivations and challenges to prescribing; 3) New options and opportunities for care but not enough to 'win the arms race'; 4) Lack of implementation support and resources; 5) Limited infrastructure.

CONCLUSIONS

BC's implementation of RMG was limited in scope, prescriber uptake and geographic scale up. Systemic, organizational and individual barriers and facilitators point to the importance of engaging professional regulatory colleges, implementation planning and organizational infrastructure to ensure effective implementation and adaptation to context.

Prescribing practices in opioid agonist treatment and changes in compliance to clinical dosing guidelines in British Columbia, Canada

BACKGROUND AND AIM

In British Columbia, Canada, clinical guidelines for the treatment of opioid use disorders (OUD) were updated in 2017, during a period in which the potency and composition of the illicit drug supply changed rapidly. We aimed to describe changes in opioid agonist treatment (OAT) prescribing practices at the population level in a setting in which fentanyl and its analogs have become the primary illicit opioid of use.

DESIGN, SETTING AND PARTICIPANTS

This was a population-based retrospective cohort study using three linked health administrative databases in British Columbia (BC), Canada. All individuals with at least one OAT dispensation in BC between 1 January 2014 and 31 August 2021 took part.

MEASUREMENTS

To assess changes in OAT prescribing practices over time, we calculated initiation doses, dose titration intervals, maintenance doses and take-home dosing intervals stratified by medication [methadone, buprenorphine-naloxone and slow-release oral morphine (SROM)] according to recommended guidelines.

FINDINGS

A total of 265 410 OAT episodes (57.5% on methadone, 34.5% on buprenorphine-naloxone and 8.0% on SROM) were initiated during the study period. Compared with the guideline recommendation, observed initiation doses were higher among all medications from 2014 (2017 for SROM) to 2021 (buprenorphine-naloxone: 14-29%; methadone: 53-66%; SROM: 26-55%). Titration intervals were shorter for all medications, consistent with guidelines for buprenorphine-naloxone (26-49%), but shorter than recommended for methadone or SROM (28-51% and 12-41%, respectively). Higher maintenance dosing was observed for methadone (68-78%) and SROM (3-21%). Take-home allowances extending beyond the recommended guideline length increased across medications (buprenorphine-naloxone: 18-35%; methadone: 50-64%; SROM: 34-39%). Changes in prescribing patterns were similar for first-time OAT initiators.

CONCLUSION

In British Columbia, Canada, from 2014 to 2021, prescribers of opioid agonist treatment (OAT) appeared to initiate both new and experienced OAT clients at higher doses than guideline recommendations, titrate them more rapidly and maintain clients at higher doses. Take-home dose allowances also gradually increased.

"And this is the life jacket, the lifeline they've been wanting": Participant perspectives on navigating challenges and successes of prescribed safer supply

BACKGROUND

In 2021, 43% of drug toxicity deaths in Ontario were reported by public health units serving medium-sized urban and rural communities. Safer supply programs (SSPs) have been primarily established in large urban centres. Given this, the current study is based on an evaluation of a SSP based in a medium-sized urban centre with a large catchment area that includes rural and Indigenous communities. The aim of this research paper is to understand the challenges and successes of the nurse practitioner-led SSP from the perspective of program participants.

METHODS

Interpretive description was used to understand the experiences of 14 participants accessing a SSP. Each participant was interviewed using a semi-structured approach, and 13 of the interviewees also completed surveys accessed through Qualtrics. An iterative process using NVivo software was used to code interviews, and a constant comparative data analysis approach was used to refine and categorize codes to themes.

FINDINGS

Three overarching themes were the result of this analysis: feeling better, renewed hope, and safety. These three themes capture the experiences of participants in the SSP, including both the challenges and successes they faced.

CONCLUSION

The findings and subsequent discussion focus on both the key best practices of the program, and areas for future development and improvement. Despite barriers to services, prescribed SSPs are improving the lives of people who use drugs, and the current outcomes align with reports and evaluations from other SSPs across Canada.

Canadian Addiction Treatment Centre (CATC) opioid agonist treatment cohort in Ontario, Canada

PURPOSE

The Canadian Addiction Treatment Centre (CATC) cohort was established during a period of increased provision of opioid agonist treatment (OAT), to study patient outcomes and trends related to the treatment of opioid use disorder (OUD) in Canada. The CATC cohort's strengths lie in its unique physician network, shared care model and event-level data, making it valuable for validation and integration studies. The CATC cohort is a valuable resource for examining OAT outcomes, providing insights into substance use trends and the impact of service-level factors.

PARTICIPANTS

The CATC cohort comprises 32 246 people who received OAT prescriptions between April 2014 and February 2021, with ongoing tri-annual updates planned until 2027. The cohort includes data from all CATC clinics' electronic medical records and includes demographic information and OAT clinical indicators.

FINDINGS TO DATE

This cohort profile describes the demographic and clinical characteristics of patients being treated in a large OAT physician network. As well, we report the longitudinal OAT retention by treatment type during a time of increasing exposure to a contaminated dangerous drug supply. Notable findings also include retention differences between methadone (32% of patients at 1 year) and buprenorphine (20% at 1 year). Previously published research from this cohort indicated that patient-level factors associated with retention include geographic location, concurrent substance use and prior treatment attempts. Service-level factors such as telemedicine delivery and frequency of urine drug screenings also influence retention. Additionally, the cohort identified rising OAT participation and a substantial increase in fentanyl use during the COVID-19 pandemic.

FUTURE PLANS

Future research objectives are the longitudinal evaluation of retention and flexible modelling techniques that account for the changes as patients are treated with OAT. Furthermore, future research aims are the use of conditional models, and linkage with provincial-level administrative datasets.

A qualitative assessment of tablet injectable opioid agonist therapy (TiOAT) in rural and smaller urban British Columbia, Canada: Motivations and initial impacts

BACKGROUND

The evolving and unpredictable unregulated drug market has driven an unprecedented overdose crisis that requires effective intervention. Growing evidence suggests that novel opioid agonist treatments, such as tablet injectable opioid agonist therapy (TiOAT), have potential to prevent overdoses and other drug-related harms. More evidence is needed to characterize their utility in achieving these outcomes. The current article is an analysis of two TiOAT programs implemented in British Columbia, Canada, to assess impact on health and well-being, including overdose risk. Moreover, we explored participants' enrollment goals and if they were achieved.

METHODS

The study employed qualitative methods to evaluate the TiOAT program in two sites between October 2021 and April 2022. We developed a semi-structured interview tool to guide in depth interviews. All interviews (n = 32) took place on teleconference software or in person. Thematic analysis allowed for the emergence of themes associated with TiOAT participation.

RESULTS

Participants discussed various motivations for enrolling in TiOAT, which included gaining financial stability, reducing or eliminating drug use, addressing withdrawal symptoms, wanting to work, and improving social circumstances. An assessment of initial programmatic impacts revealed that many participant-identified motivators were achieved. Participants also reported fewer or no overdoses since starting TiOAT, and many reported switching from injecting to smoking drugs. Some challenges included adequate dosing as evidenced by ongoing withdrawal and pain. Some participants requested additional opioids, such as diacetylmorphine, to aid in reducing illicit drug use.

CONCLUSION

Participants described how TiOAT helped them to achieve many of their goals. Suggested programmatic improvements include enhanced patient-provider co-design with respect to dosing to address ongoing withdrawal and pain. As the unpredictability the unregulated drug market worsens, novel options, such as TiOAT, ought to be implemented broadly to reduce overdose events and improve quality of life for people who use drugs.

The Impact of Injectable Opioid Agonist Treatment (iOAT) on Involvement in Criminalized Activities: A Secondary Analysis from a Clinical Trial in Vancouver, BC

Purpose

A significant portion of the economic consequences of untreated Opioid Use Disorder (OUD) relate to individuals' involvement in the criminal justice system. The present study uncovers if treatment with iOAT is related to the number of criminal charges amongst participants, what type of crime participants were involved in, and the frequency with which participants were victims of crime. This study contributes to the body of research on the effectiveness of iOAT reducing criminal involvement.

Patients and Methods

This is a secondary analysis of police record data obtained from the Vancouver Police Department over a three-year period during the Study to Assess Longer-term Opioid Medication Effectiveness clinical trial. The data was obtained from participants (N = 192) enrolled in the trial through a release of information form.

Results

During the three-year period, most charges (45.6%) were property offences, and 25.5% of participants were victims of crime. Participants with no treatment prior to randomization into the SALOME trial were 2.61 (95% CI = 1.64-4.14) more likely to have been charged with a crime than during the iOAT state.

Conclusion

IOAT can reduce individuals' involvement with the criminal justice system and is thus a crucial part of the continuum of care. Addiction should be conceptualized as a healthcare rather than criminal issue.

Racial/ethnic disparities in timely receipt of buprenorphine among Medicare disability beneficiaries

BACKGROUND

Medicare disability beneficiaries (MDBs) have disproportionately high risk of opioid use disorder (OUD) and related harms given high rates of comorbidities and high-dose opioid prescribing. Despite this increased risk, little is known about timely receipt of medication for opioid use disorder (MOUD), including potential disparities by patient race/ethnicity or moderation by county-level characteristics.

METHODS

National Medicare claims for a sample of MDBs with incident OUD diagnosis between March 2016 and June 2019 were linked with county-level data. Multivariable mixed effects Cox proportional hazards models estimated time (in days) to buprenorphine receipt within 180 days of incident OUD diagnosis. Primary exposures included individual-level race/ethnicity and county-level buprenorphine prescriber availability, percent non-Hispanic white (NHW) residents, and Social Deprivation Index (SDI) score.

RESULTS

The sample (n=233,079) was predominantly White (72.3%), ≥45 years old (76.3%), and male (54.8%). Black (adjusted hazard ratio [aHR]=0.50; 95% CI, 0.47-0.54), Asian/Pacific Islander (aHR=0.54; 95% CI, 0.41-0.72), Hispanic/Latinx (aHR=0.81; 95% CI, 0.76-0.87), and Other racial/ethnic groups (aHR=0.75; 95% CI, 0.58-0.97) had a lower likelihood of timely buprenorphine than non-Hispanic white beneficiaries after adjusting for individual and county-level confounders. Timely buprenorphine receipt was positively associated with county-level buprenorphine prescriber availability (aHR=1.05; 95% CI, 1.04-1.07), percent non-Hispanic white residents (aHR=1.01; 95% CI, 1.00-1.01), and SDI (aHR=1.06; 95% CI, 1.01-1.10).

CONCLUSIONS

Racial/ethnic disparities highlight the need to improve access to care for underserved groups. Implementing equity-focused quality and performance measures and developing interventions to increase office-based buprenorphine prescribing in predominantly minority race/ethnicity counties may reduce disparities in timely access to medication for OUD.

'I don't chase drugs as much anymore, and I'm not dead': Client reported outcomes associated with safer opioid supply programs in Ontario, Canada

INTRODUCTION

The ongoing opioid overdose crisis, which has killed over 30,000 people in Canada since 2016, is driven by the volatility of an unregulated opioid drug supply comprised primarily of fentanyl. The Canadian government has recently funded safer opioid supply (SOS) programs, which include off-label prescriptions of pharmaceutical-grade opioids to high risk individuals with the goal of reducing overdose deaths.

METHODS

In 2021, we examined the implementation and adaption of four SOS programs in Ontario. These programs use a primary care model and serve communities experiencing marginalisation. We conducted semi-structured interviews with program clients. We present the results of a thematic analysis with the aim of describing clients' self-reported impact of these programs on their health and well-being.

RESULTS

We interviewed 52 clients between June and October 2021 (mean age 47 years, 56% men, 17% self-identified Indigenous, 14% living with HIV). Our results indicate multifaceted pathways to improved self-reported health and well-being among clients including changes to drug use practices, fewer overdoses, reduced criminalised activity, improved trust and engagement in health care, and increased social stability (e.g., housing).

DISCUSSION AND CONCLUSION

Most clients reported that the intervention saved their life because of the reduced frequency of overdoses. Findings suggest that SOS programs improved clients' health outcomes and increase opportunities for engagement in health services. Our results provide insight into the mechanisms behind some of the emergent evidence on the impact of safer supply prescribing.

Using a cascade of care framework to identify gaps in access to medications for alcohol use disorder in British Columbia, Canada

BACKGROUND AND AIMS

Despite the significant burden of alcohol use disorder (AUD) and availability of safe and effective medications for AUD (MAUD), population-level estimates of access and engagement in AUD-related care are limited. The aims of this study were to generate a cascade of care for AUD in British Columbia (BC), Canada, and to estimate the impacts of MAUD on health outcomes.

DESIGN

This was a retrospective population-based cohort study using linked administrative health data.

SETTING

British Columbia, Canada, 2015-2019.

PARTICIPANTS

Using a 20% random sample of BC residents, we identified 7231 people with moderate-to-severe alcohol use disorder (PWAUD; overall prevalence = 0.7%).

MEASUREMENTS

We developed a six-stage AUD cascade (from diagnosis to ≥6 months retention in MAUD) among PWAUD. We evaluated trends over time and estimated the impacts of access to MAUD on AUD-related hospitalizations, emergency department visits and death.

FINDINGS

Between 2015 and 2019, linkage to AUD-related care decreased (from 80.4% to 46.5%). However, rates of MAUD initiation (11.4% to 24.1%) and retention for ≥1 (7.0% to 18.2%), ≥3 (1.2% to 4.3%) or ≥6 months (0.2% to 1.6%) increased significantly. In adjusted analyses, access to MAUD was associated with reduced odds of experiencing any AUD-related adverse outcomes, with longer retention in MAUD showing a trend to greater odds reduction: adjusted odds ratio (95% CI) ranging from 0.59 (0.48-0.71) for MAUD retention <1 month to 0.37 (0.21-0.67) for ≥6 months retention.

CONCLUSIONS

Access to medications for alcohol use disorder among people with moderate-to-severe alcohol use disorder in British Colombia, Canada increased between 2015 and 2019; however, initiation and retention remained low. There was a trend between longer retention in medications for alcohol use disorder and greater reductions in the odds of experiencing alcohol use disorder-related adverse outcomes.

Treatment Initiation, Substance Use Trajectories, and the Social Determinants of Health in Persons Living With HIV Seeking Medication for Opioid Use Disorder

BACKGROUND

People living with HIV and opioid use disorder (OUD) are disproportionally affected by adverse socio-structural exposures negatively affecting health, which have shown inconsistent associations with uptake of medications for OUD (MOUD). This study aimed to determine whether social determinants of health (SDOH) were associated with MOUD uptake and trajectories of substance use in a clinical trial of people seeking treatment.

METHODS

Data are from a 2018 to 2019 randomized trial comparing the effectiveness of different MOUD to achieve viral suppression among people living with HIV and OUD. SDOH were defined by variables mapping to Healthy People 2030 domains: education (Education Access and Quality), income (Economic Stability), homelessness (Neighborhood and Built Environment), criminal justice involvement (Social and Community Context), and recent SUD care (Health Care Access and Quality). Associations between SDOH and MOUD initiation were assessed with Cox proportional hazards models, and SDOH and substance use over time with generalized estimating equation models.

RESULTS

Participants (N = 114) averaged 47 years old, 63% were male, 56% were Black, and 12% Hispanic. Participants reported an average of 2.3 out of 5 positive SDOH indicators (SD = 1.2). Stable housing was the most commonly reported SDOH (61%), followed by no recent criminal justice involvement (59%), having a high-school level education or greater (56%), income stability (45%), and recent SUD care (13%). Each additional favorable SDOH was associated with a 25% increase in the likelihood of MOUD initiation during the study period [adjusted HR = 1.25, 95% CI = (1.01, 1.55), P = .044]. Positive SDOH were also associated with a decrease in the odds of baseline opioid use and a greater reduction in opioid use during subsequent weeks of the study (P < .001 for a joint test of baseline and slope differences).

CONCLUSIONS

Positive social determinants of health, in aggregate, may increase the likelihood of MOUD treatment initiation among people living with HIV and OUD.

Opioid agonist therapy and mortality among First Nations and other residents with concurrent alcohol use disorder in British Columbia, Canada: A population-based cohort study

BACKGROUND

Despite the prevalence of alcohol use among people with opioid use disorder (PWOUD) engaged in opioid agonist therapy (OAT), clinical care guidance for concurrent alcohol use disorder (AUD) and OUD is scarce. We assessed the prevalence and risk of mortality for concurrent AUD among PWOUD who accessed OAT in British Columbia (BC).

METHODS

Data were obtained from six linked population-level health administrative datasets to identify PWOUD from January 1996 to March 2020. All-cause age and sex standardized mortality ratios (SMR) were calculated to determine the mortality risk by OAT status (on vs. discontinued), stratified by First Nations and other residents with concurrent AUD and OUD. Adjusted risk ratios compared the relative risk of mortality by AUD status (AUD detected vs. not) among First Nations and other residents.

RESULTS

We identified 62,110 PWOUD who received OAT, including 6305 (10.2%) First Nations. OAT substantially lowered the SMR among First Nations (SMR=6.6, 95% CI: 5.4-8.1) and other residents (SMR=6.6; 95% CI: 6.2-7.0) with concurrent AUD and OUD, compared to those who discontinued (SMR=22.7, 95% CI: 20.4-25.1, SMR=17.5, 95% CI: 16.8-18.2 respectively). The risk of mortality was 1.9 (95% CI: 1.6-2.2) times higher for First Nations and 2.0 (95% CI: 1.8-2.2) times higher for other residents with concurrent OUD and AUD compared to those without an indication of AUD.

CONCLUSIONS

The protective effect of OAT remained despite the presence of a concurrent AUD among both First Nations and other residents with OUD. Findings have implications for clinical care management of concurrent disorders.

Availability of timely methadone treatment in the United States and Canada during COVID-19: A census tract-level analysis

OBJECTIVES

We sought to compare timely access to methadone treatment in the United States (US) and Canada during the COVID-19 pandemic.

METHODS

We conducted a cross-sectional study of census tracts and aggregated dissemination areas (used for rural Canada) within 14 US and 3 Canadian jurisdictions in 2020. We excluded census tracts or areas with a population density of less than one person per square km. Data from a 2020 audit of timely medication access was used to determine clinics accepting new patients within 48 h. Unadjusted and adjusted linear regressions were performed to examine the relationship between area population density and sociodemographic covariates and three outcome variables: 1) driving distance to the nearest methadone clinic accepting new patients, 2) driving distance to the nearest methadone clinic accepting new patients for medication initiation within 48 h, and 3) the difference in the driving distance between the first and second outcome.

RESULTS

We included 17,611 census tracts and areas with a population density greater than one person per square kilometer. After adjusting for area covariates, US jurisdictions were a median of 11.6 miles (p value <0.001) further from a methadone clinic accepting new patients and 25.1 miles (p value <0.001) further from a clinic accepting new patients within 48 h than Canadian jurisdictions.

CONCLUSIONS

These results suggest that the more flexible Canadian regulatory approach to methadone treatment is associated with a greater availability of timely methadone treatment and reduced urban-rural disparity in availability, compared to the US.

Transitions in care between hospital and community settings for individuals with a substance use disorder: A systematic review

BACKGROUND AND AIMS

Individuals with a substance use disorder (SUD) have high rates of hospital service utilization including emergency department (ED) presentations and hospital admissions. Acute care settings offer a critical opportunity to engage individuals in addiction care and improve health outcomes especially given that the period of transition from hospital to community is challenging. This review summarizes literature on interventions for optimizing transitions in care from hospital to community for individuals with a SUD.

METHODS

The literature search focused on key terms associated with transitions in care and SUD. The search was conducted on three databases: MEDLINE, CINAHL, and PsychInfo. Eligible studies evaluated interventions acting prior to or during transitions in care from hospital to community and reported post-discharge engagement in specialized addiction care and/or return to hospital and were published since 2010.

RESULTS

Title and abstract screening were conducted for 2337 records. Overall, 31 studies met inclusion criteria, including 7 randomized controlled trials and 24 quasi-experimental designs which focused on opioid use (n = 8), alcohol use (n = 5), or polysubstance use (n = 18). Interventions included pharmacotherapy initiation (n = 7), addiction consult services (n = 9), protocol implementation (n = 3), screening, brief intervention, and referral to treatment (n = 2), patient navigation (n = 4), case management (n = 1), and recovery coaching (n = 3).

CONCLUSIONS

Both pharmacologic and psychosocial interventions implemented around transitions from acute to community care settings can improve engagement in care and reduce hospital readmission and ED presentations. Future research should focus on long-term health and social outcomes to improve quality of care for individuals with a SUD.

Identifying Longitudinal CD4:CD8 Ratio Trajectories Indicative of Chronic Renal Disease Risk among People Living with HIV: An Application of Growth Mixture Models

The incidence of chronic kidney disease (CKD) is increasing among people living with HIV (PLWH). Routine monitoring of indicators such as CD4:CD8 ratio might improve the early detection of CKD. Our objective was to identify clinically relevant CD4:CD8 ratio trajectories indicative of CKD risk. Participants were ≥ 18 years old, initiated antiretroviral therapy between 2000 and 2016, and were followed for ≥6 months until 31 March 2017 or last contact date. Outcome was incidence of CKD. Growth mixture models (GMMs) and decay models were used to compare CD4:CD8 ratio trajectories. Following GMM, 4547 (93.5%) participants were classified in Class 1 with 5.4% developing CKD, and 316 (6.5%) participants were classified in Class 2 with 20.9% developing CKD. The final model suggested that participants in Class 2 had 8.72 times the incidence rate of developing CKD than those in Class 1. Exponential decay models indicated a significant CD4:CD8 ratio decline among Class 2 participants who developed CKD. Among those who developed CKD in Class 2, starting at 5.5 years of follow-up, the slope of their ratio trajectory curve changed significantly, and the rate of decline increased dramatically. Routine monitored CD4:CD8 ratios can be an effective strategy to identify early CKD risk among PLWH.

Concurrent use of opioids and stimulants and risk of fatal overdose: A cohort study

Background

Stimulant use has been rising among people with opioid use disorder in recent years in North America, alongside a parallel rise in illicit drug toxicity (overdose) deaths. This study aimed to examine the association between stimulant use and overdose mortality.

Methods

Data from a universal health insurance client roster were used to identify a 20% random general population sample (aged ≥12) in British Columbia, Canada between January 1 2015 and December 31 2018 (N = 1,089,682). Provincial health records were used to identify people who used opioids and/or stimulants. Fatal overdose observed during follow-up (January 12,015- December 312,018) was retrieved from Vital Statistics Death Registry and BC Coroners Service Data. Potential confounders including age, sex, health region, comorbidities and prescribed medications were retrieved from the provincial client roster and health records.

Results

We identified 7460 people who used stimulants and or opioids. During follow-up there were 272 fatal overdose events. People who used both opioids and stimulants had more than twice the hazard of fatal overdose (HR: 2.02, 95% CI: 1.47-2.78, p < 0.001) compared to people who used opioids only. The hazard of death increased over time among people who used both opioids and stimulants.

Conclusions

There is an urgent need to prioritize the service needs of people who use stimulants to reduce overdose mortality in British Columbia. Findings have relevance more broadly in other North American settings, where similar trends in opioid and stimulant polysubstance use have been observed.

Association of opioid use disorder with healthcare utilization and cost in a public health system

AIM

To quantify the healthcare costs associated with opioid use disorder among members in a public healthcare system and compare them with healthcare costs in the general population.

DESIGN

Retrospective cohort study.

SETTING

Inpatient and outpatient care settings of Israel's largest public healthcare provider (that covers 4.7 million members).

PARTICIPANTS

Participants included 1173 members who had a diagnosis of opioid use disorder in the years between 2013 and 2018. Each patient was matched with 10 controls based on age and sex.

MEASUREMENTS

The main outcome was monthly healthcare costs.

FINDINGS

The mean monthly healthcare cost of members with opioid use disorder was $1102 compared with $211 among controls (5.2-fold difference; 95% CI, 4.6-6.0). After excluding members with heroin related diagnoses before the index date (to focus on prescription opioids), this healthcare cost ratio did not substantially change (4.6-fold; 95% CI, 3.9-5.4). Members with opioid use disorder under the age of 65 years had a cost difference of 6.1-fold (95% CI, 5.2-7.1), whereas those 65 years and older experienced cost difference of 3.4-fold (95% CI, 2.6-4.5), compared with controls. The category with the highest cost for members with opioid use disorder was inpatient services, which was 8.7-fold (95%CI, 7.2-10.4) greater than among controls.

CONCLUSIONS

Healthcare costs among individuals with opioid use disorder in Israel's public health system are substantially higher than among controls, at least partially attributable to prescription opioid use disorder. Differences are greater among individuals under 65 years.

Advancing virtual primary care for people with opioid use disorder (VPC OUD): a mixed-methods study protocol

INTRODUCTION

The emergence of COVID-19 introduced a dual public health emergency in British Columbia, which was already in the fourth year of its opioid-related overdose crisis. The public health response to COVID-19 must explicitly consider the unique needs of, and impacts on, communities experiencing marginalisation including people with opioid use disorder (PWOUD). The broad move to virtual forms of primary care, for example, may result in changes to healthcare access, delivery of opioid agonist therapies or fluctuations in co-occurring health problems that are prevalent in this population. The goal of this mixed-methods study is to characterise changes to primary care access and patient outcomes following the rapid introduction of virtual care for PWOUD.

METHODS AND ANALYSIS

We will use a fully integrated mixed-methods design comprised of three components: (a) qualitative interviews with family physicians and PWOUD to document experiences with delivering and accessing virtual visits, respectively; (b) quantitative analysis of linked, population-based administrative data to describe the uptake of virtual care, its impact on access to services and downstream outcomes for PWOUD; and (c) facilitated deliberative dialogues to co-create educational resources for family physicians, PWOUD and policymakers that promote equitable access to high-quality virtual primary care for this population.

ETHICS AND DISSEMINATION

Approval for this study has been granted by Research Ethics British Columbia. We will convene PWOUD and family physicians for deliberative dialogues to co-create educational materials and policy recommendations based on our findings. We will also disseminate findings via traditional academic outputs such as conferences and peer-reviewed publications.

Opioid agonist treatment improves progression through the HIV cascade of care among people living with HIV who use unregulated opioids

OBJECTIVES

Opioid agonist treatment (OAT) has been shown to improve certain HIV-related treatment measures among people with HIV (PHIV) with opioid use disorder (OUD). However, there is limited data on the impacts of OAT along the whole HIV cascade of care.

DESIGN AND METHODS

Using data from an ongoing cohort of PHIV who use drugs in Vancouver, Canada, we used cumulative link mixed-effects models to estimate the independent effect of OAT on achieving progressive steps in the HIV cascade among participants using unregulated opioids daily, after adjusting for confounders.

RESULTS

Between 2005 and 2017, we recruited 639 PHIV regularly using opioids (median age 42 years, 59% male, 56% White), of whom 70% were on OAT at their baseline visit. Engagement in OAT showed a nonsignificant trend with higher linkage to HIV care (adjusted partial proportional odds ratio [APPO] = 1.75, 95% confidence interval [CI]: 0.83-3.69), and significantly higher cumulative odds of successfully achieving subsequent HIV cascade steps: on ART (APPO = 3.85, 95% CI: 2.33-6.37); adherent to ART (APPO = 3.15, 95% CI: 2.15-4.62); and HIV viral suppression (APPO = 2.18, 95% CI: 1.51-3.14).

CONCLUSIONS

This study found a high level of OAT engagement among PHIV using unregulated opioids and that OAT engagement resulted in significantly increased progression through some of the higher steps of the HIV cascade. While these findings are encouraging, they highlight the need to reach populations off OAT to maximize the clinical and community-level benefits of ART.

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.

Factors associated with 60-day adherence to "safer supply" opioids prescribed under British Columbia's interim clinical guidance for health care providers to support people who use drugs during COVID-19 and the ongoing overdose emergency

AIMS

In March 2020, British Columbia issued Risk Mitigation Guidance (RMG) to support prescribing of pharmaceutical alternatives to illicit drugs, in order to reduce risk for COVID-19, overdose, and withdrawal among people who use drugs. This study evaluated factors associated with 60-day adherence to novel opioid alternatives prescribed at an inner-city health centre in Victoria, Canada.

METHODS

A chart review was conducted to collect data on sociodemographic information, medical histories, and follow-up services among all clients prescribed novel opioid alternatives from March 2020-August 2020 (n = 286). Bivariable and multivariable regression were used to identify independent and adjusted factors associated with 60-day adherence.

RESULTS

Overall, 77% of 286 clients were still receiving opioids after 60 days of follow-up. Medications included hydromorphone (n = 274), sustained-release oral morphine (n = 2), and oxycodone (n = 9). The adjusted odds of 60-day adherence to novel opioid alternatives were significantly higher for those receiving a mental health medication (aOR = 3.49, 95%CI = 1.26, 11.00), a higher maximum daily dosage of RMG prescriptions (aOR = 1.03 per mg increase, 95%CI = 1.01, 1.04), and those with continuous receipt of OAT (aOR = 6.25, 95%CI = 2.67, 15.90).

CONCLUSIONS

Higher dosages and co-prescription of mental health medications and OAT may help support better adherence to this form of prescriber-based "safer supply". Further work is needed to identify optimal prescribing practices and the longer term impacts of differing implementation scenarios.

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.

“We need to build a better bridge”: findings from a multi-site qualitative analysis of opportunities for improving opioid treatment services for youth

Background

Adolescence and young adulthood is an important period for substance use initiation and related harms. In the context of the ongoing opioid crisis, the risks for youth (ages 16–29) who use opioids are particularly heightened. Despite recommendations to adopt a developmentally appropriate and comprehensive approach to reduce opioid-related harms among youth, data continue to show that youth are not adequately engaged in opioid treatments and encounter many barriers. The aim of this study is to identify youth-centered opportunities for improving opioid treatment services.

Methods

This paper reports multi-site qualitative findings from youth participating in the ‘Improving Treatment Together’ project, a community-based participatory project being conducted in British Columbia and Alberta, two western Canadian provinces that have been dramatically impacted by the opioid crisis. Qualitative data were collected during three workshops with youth who used opioids and accessed opioid treatment services in the prior 12 months. These workshops were conducted in three communities following the core elements of human-centered co-design. A multi-site qualitative analysis was conducted to identify within- and between-site themes surrounding youths’ needs for improving opioid treatment service experiences and outcomes.

Results

Three overarching needs themes were identified from across the communities. The first reflected youths’ difficulties finding and staying connected to opioid treatment services, with the overarching need theme suggesting opportunities to reduce organizational and systems-related barriers to care, such as waiting times and wider information about service availability. The second area of need was rooted in youths’ feelings of judgment when accessing services. Consequently, opportunities to increase respectful and empathic interactions were the overarching need. The final theme was more nuanced across communities and reflected opportunities for an individualized approach to opioid treatment services that consider youths’ unique basic safety, social, and health needs.

Conclusions

This study identifies fundamental directions for the operationalization and implementation of youth-centered opioid treatment services. These directions are contextualized in youths’ lived experiences accessing services in their local communities, with overarching themes from across sites strengthening their transferability to other settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-022-00623-7.

Measuring treatment attrition at various stages of engagement in Opioid Agonist Treatment in Ontario Canada using a cascade of care framework

Background

The cascade of care framework is an effective way to measure attrition at various stages of engagement in Opioid Agonist Treatment (OAT). The primary objective of the study was to describe the cascade of care for patients who have accessed OAT from a network of specialized addiction clinics in Ontario, Canada. The secondary objectives were to evaluate correlates associated with retention in OAT at various stages and the impact of patients’ location of the residence on retention in OAT.

Design

A multi-clinic retrospective cohort study was conducted using electronic medical record (EMR) data from the largest network of OAT clinics in Canada (70 clinics) from 2014 to 2020. Study participants included all patients who received OAT from the network of clinics during the study period.

Measurements

In this study, four stages of the cascade of care framework were operationalized to identify treatment engagement patterns, including patients retained within 90 days, 90 to 365 days, one to 2 years, and more than 2 years. Correlates associated with OAT retention for 90 days, 90 to 365 days, 1 to 2 years, and more than 2 years were also evaluated and compared across rural and urban areas in northern and southern Ontario.

Results

A total of 32,487 patients were included in the study. Compared to patients who were retained in OAT for 90 days, patients who were retained for 90 to 365 days, 1 to 2 years, or more than 2 years were more likely to have a higher number of treatment attempts, a higher number of average monthly urine drug screening and a lower proportion of positive urine drug screening results for other drug use.

Conclusion

Distinct sociodemographic and clinical factors are likely to influence treatment retention at various stages of engagement along the OAT continuum. Research is required to determine if tailored strategies specific to people at different stages of retention have the potential to improve outcomes of OAT.

Development and validation of health system performance measures for opioid use disorder in British Columbia, Canada

BACKGROUND

Performance measurement provides an evidence-based means to inform development of interventions to improve the quality of care for people who use opioids. We aimed to develop and assess the predictive validity of health system performance measures for opioid use disorder (OUD) in British Columbia (BC), Canada.

METHODS

Performance measures were generated using retrospective population-level administrative datasets (both provincial and regional) and publicly-reported retrospective data according to four domains (care engagement, clinical guideline compliance, integration, and healthcare utilization). The adjusted odds ratio was estimated via generalized linear mixed models to determine predictive validity for all-cause hospitalization or mortality within 6 months of measurement.

FINDINGS

A total of 102 performance measures were constructed. We identified 55,470 diagnosed PWOUD, and 39,456 ever engaged in opioid agonist treatment (OAT). We found divergent rates of treatment for concurrent conditions (7.4% for alcohol use disorder to 80.1% for HIV/AIDS), low levels of linkage to OAT and other outpatient care following acute care, and increasing levels of service provision, including increases in OAT prescribers and pharmacies, naloxone kit distribution and overdose prevention site visitation. Our analyses on the predictive validity measures largely supported a priori hypotheses on the direction of effect on the outcome.

CONCLUSIONS

We identified a range of priorities to improve the quality of care for PWOUD, with critical gaps in linkage to care through acute care settings and long-term engagement in OAT. The proposed measures can be derived for geographic and clinical subgroups and updated over time, providing a basis to monitor and evaluate efforts to address the public health burden of OUD.

Feasibility of Testing Client Preferences for Accessing Injectable Opioid Agonist Treatment (iOAT): A Pilot Study

PURPOSE

Injectable opioid agonist treatment (iOAT) is an effective treatment for opioid use disorder (OUD). To our knowledge, no research has systematically studied client preferences for accessing iOAT. Incorporating preferences could help meet the heterogenous needs of clients and make addiction care more person-centred. This paper presents a pilot study of a best-worst scaling (BWS) preference elicitation survey that aimed to assess if the survey was feasible and accessible for our population and to test that the survey could gather sound data that would suit our planned analyses.

PATIENTS AND METHODS

Current and former iOAT clients (n = 18) completed a BWS survey supported by an interviewer using a think-aloud approach. The survey was administered on PowerPoint, and responses and contextual field notes were recorded manually. Think-aloud audio was recorded on Audacity.

RESULTS

Clients' feedback fell into five categories: framing of the task, accessibility, conceptualization of attributes and levels, formatting, and behaviour predicting questions. Survey repetitiveness was the most consistent feedback. The data simulation showed that 100 responses should provide an adequate sample size.

CONCLUSION

This pilot demonstrates the type of analysis that can be done with BWS in our population, suggests that such analysis is feasible, and highlights the importance of the interviewer and participant working side-by-side throughout the task.

Opioid use disorder Cascade of care framework design: A roadmap

Unintentional overdose deaths, most involving opioids, have eclipsed all other causes of US deaths for individuals less than 50 years of age. An estimated 2.4 to 5 million individuals have opioid use disorder (OUD) yet a minority receive treatment in a given year. Medications for OUD (MOUD) are the gold standard treatment for OUD however early dropout remains a major challenge for improving clinical outcomes. A Cascade of Care (CoC) framework, first popularized as a public health accountability strategy to stem the spread of HIV, has been adapted specifically for OUD. The CoC framework has been promoted by the NIH and several states and jurisdictions for organizing quality improvement efforts through clinical, policy, and administrative levers to improve OUD treatment initiation and retention. This roadmap details CoC design domains based on available data and potential linkages as individual state agencies and health systems typically rely on limited datasets subject to diverse legal and regulatory requirements constraining options for evaluations. Both graphical decision trees and catalogued studies are provided to help guide efforts by state agencies and health systems to improve data collection and monitoring efforts under the OUD CoC framework.

Opioid analgesic prescribing for opioid-naïve individuals prior to identification of opioid use disorder in British Columbia, Canada

BACKGROUND AND AIMS

Prescription opioid analgesics have contributed to the development of opioid use disorder (OUD) in many individuals. We aimed to characterize non-cancer opioid prescribing for opioid-naive individuals prior to OUD identification.

DESIGN

Population-based retrospective cohort study using six linked health administrative databases.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

People with OUD between 1 January 2001 and 30 September 2018 who initiated opioid analgesic therapy for non-cancer pain prior to OUD identification.

MEASUREMENTS

Dose (morphine milligram equivalent per day), days prescribed and clinical guideline non-concordance for initial opioid prescriptions (dose ≥ 90 morphine milligram equivalent per day; ≥ 7 days prescribed; concomitant sedative prescription). We estimated the probability of non-concordant initial prescriptions by source (inpatient post-discharge, non-inpatient acute, non-acute) using logistic regression, adjusting for individual characteristics and comorbidities.

FINDINGS

Among 66 372 individuals identified with OUD from 2001 to 2018, 21 331 (32.1%) received opioid analgesics prior to OUD identification. This proportion increased from 3.0% in 2001 to 41.0% in 2011, before decreasing to 34.2% in 2017. Roughly half of opioid prescriptions were attributed to non-acute care visits, peaking at 56.8% in 2007, while the proportion from inpatient visits increased from 19.7% in 2001 to 28.5% in 2017. The predicted probability of receiving non-guideline concordant prescriptions declined over time-periods across all three measures for inpatient and non-inpatient acute care, while remaining stable for non-acute care. In particular, the predicted probability of receiving ≥ 7-day prescriptions following inpatient visits decreased from 53.3% [95% confidence interval (CI) = 50.9, 55.8%] in 2001-06 to 37.2% (95% CI = 33.9, 40.5%) in 2013-18.

CONCLUSIONS

Among the 66 372 individuals in British Columbia, Canada diagnosed with opioid use disorder between 2001 and 2018, more than 32% were earlier prescribed non-cancer opioid analgesics. The proportion who had received an opioid analgesic prescription prior to OUD identification peaked at more than 40% in 2011, before stabilizing between 2011 and 2016 and declining thereafter. Guideline concordance improved over time for high-dose and concomitant sedative prescribing.

The use of diverted pharmaceutical opioids is associated with reduced risk of fentanyl exposure among people using unregulated drugs in Vancouver, Canada

BACKGROUND

Although non-medical use of pharmaceutical opioids (POs) is associated with a number of risks, in the context of the opioid-overdose crisis, it may have the secondary benefit of decreasing the risk of exposure to more potent opioids from unregulated sources. The aim of this study was to assess the effects of using diverted POs on fentanyl exposure.

METHODS

Using data from two prospective community-recruited cohorts of people who use drugs (PWUD) in Vancouver, Canada, we estimated the independent relationship between using diverted POs and fentanyl exposure (assessed through urine drug test [UDT]) between 2016 and 2018. We also explored if participant characteristics modified this relationship.

RESULTS

Over the study period, among 1150 participants, 241 (21.0%) reported using diverted POs in 292 (12.8%) occasions. In adjusted analyses, PWUD using diverted POs had decreased odds of fentanyl exposure (Adjusted odds ratio [AOR] = 0.70, 95% CI: 0.52-0.94). The reduced odds of fentanyl exposure persisted among participants with morphine positive UDT (AOR = 0.57, 95% CI: 0.40-0.82), but not among those with negative morphine UDT (AOR = 0.91, 95% CI: 0.54-1.55).

CONCLUSION

PWUD using diverted POs in our sample were 30% less likely to be exposed to fentanyl. This reduced likelihood was primarily observed among PWUD with morphine positive UDT, which could partially be explained by longer duration of action and lower street cost of slow-release oral morphine relative to other POs and fentanyl. Findings suggest that access to a regulated supply of pharmaceutical-grade opioids may serve to reduce fentanyl-related harms.

Evidence of Increased Age and Sex Standardized Death Rates Among Individuals Who Accessed Opioid Agonist Treatment Before the Era of Synthetic Opioids in Ontario, Canada

Objective The objective of this study was to evaluate age-sex standardized death rates (ASDR) from all causes from 2011 to 2015 among people who have accessed opioid agonist treatment (OAT) and compare rates living in the Northern and Southern areas of Ontario. Methods Routinely collected administrative health data was used to calculate crude death rates and age-sex standardized death rates (ASDRs) per 1,000,000 population of individuals who accessed OAT and compared the rates geographically from 2011 to 2015. The weighted ASDRs for each year were calculated by using the mid-year population of these regions. The rate ratios were calculated considering the base year as 2011.  Results A total of 55,924 adults who accessed OAT were included between January 1, 2011, and December 31, 2015. The majority of patients in the cohort - 52.3% - were between 15 and 34 years old, 32.5% were female, 11.3% were in the lowest income group, 71.1% lived in Southern areas. Overall, the ASDR steadily increased during the study period and spiked in 2015. We found that among individuals who had accessed OAT, living in Southern Ontario was associated with a lower risk of all-cause mortality than those living in Northern Ontario. ASDR for Northern Ontario was 20.0 (95% confidence interval (CI)= 10.2-34.2) in 2011, and 103.5(95%CI=78.5-133.5) in 2015, which was a five-fold increase from 2011. Whereas in Southern Ontario, ASDR in 2011 was 13.8 (95% CI= 11.5-16.5), and in 2015 ASDR was 60.8 (95%CI=55.8-66.1), which was only a 4-fold increase from 2011 Conclusion Our findings demonstrate evidence of a steadily increasing ASDR among individuals who accessed OAT with higher rates in Northern areas of the province before the era of synthetic opioids in Ontario, Canada.

Opioid Use Disorder and Perinatal Outcomes

OBJECTIVES

Evidence on the perinatal health of mother-infant dyads affected by opioids is limited. Elevated risks of opioid-related harms for people with opioid use disorder (OUD) increase the urgency to identify protective factors for mothers and infants. Our objectives were to determine perinatal outcomes after an OUD diagnosis and associations between opioid agonist treatment and birth outcomes.

METHODS

We conducted a population-based retrospective study among all women with diagnosed OUD before delivery and within the puerperium period in British Columbia, Canada, between 2000 and 2019 from provincial health administrative data. Controlling for demographic and clinical characteristics, we determined associations of opioid agonist treatment on birth weight, gestational age, infant disorders related to gestational age and birth weight, and neonatal abstinence syndrome via logistic regression.

RESULTS

The population included 4574 women and 6720 live births. Incidence of perinatal OUD increased from 166 in 2000 to 513 in 2019. Compared with discontinuing opioid agonist treatment during pregnancy, continuous opioid agonist treatment reduced odds of preterm birth (adjusted odds ratio: 0.6; 95% confidence interval: 0.4-0.8) and low birth weight (adjusted odds ratio: 0.4; 95% confidence interval: 0.2-0.7). Treatment with buprenorphine-naloxone (compared with methadone) reduced odds of each outcome including neonatal abstinence syndrome (adjusted odds ratio: 0.6; 95% confidence interval: 0.4-0.9).

CONCLUSIONS

Perinatal OUD in British Columbia tripled in incidence over a 20-year period. Sustained opioid agonist treatment during pregnancy reduced the risk of adverse birth outcomes, highlighting the need for expanded services, including opioid agonist treatment to support mothers and infants.

Characterizing opioid agonist treatment discontinuation trends in British Columbia, Canada, 2012-2018

BACKGROUND

Given the elevated risk of mortality immediately following opioid agonist treatment (OAT) discontinuation, determining the frequency and timing of OAT discontinuation can help guide the planning of services to facilitate uninterrupted OAT. We sought to describe weekly and monthly trends in OAT episode discontinuations in British Columbia to determine the potential resource needs for implementing support services.

METHODS

This population-based retrospective study utilized a provincial-level linkage of health administrative databases to identify all people with opioid use disorder (PWOUD) who received OAT between 01/2012-08/2018. We defined OAT episodes as continuous medication dispensations without interruptions in prescribed doses lasting ≥5 days for methadone and ≥6 days for buprenorphine/naloxone. We derived the percentage of PWOUD discontinuing OAT every month and we considered weekly discontinuations between 09/2017-08/2018, accounting for weeks during which monthly income assistance payments from social service programs occurred.

RESULTS

Our study included 37,207 PWOUD discontinuing 158,027 OAT episodes. Discontinuations were relatively stable month-to-month, increasing from 10.6 % to 14.9 % (2012-2018). The monthly percentage of discontinuations was 21.2 % for buprenorphine/naloxone and 10.0 % for methadone. Weekly discontinuations were greater in income disbursement weeks (816; IQR: 752, 901) compared to other weeks (655; IQR: 615, 683; p < 0.01).

CONCLUSIONS

We identified a high, and stable rate of monthly OAT discontinuations and a consistently higher rate of discontinuing treatment among PWOUD accessing buprenorphine/naloxone. There is an urgent need to develop the evidence base for interventions to support OAT engagement and to improve clinical management of OUD to address the opioid-related overdose crisis.

The naloxone delivery cascade: Identifying disparities in access to naloxone among people who inject drugs in Los Angeles and San Francisco, CA

BACKGROUND

Opioid overdoses are a leading cause of injury death in the United States. Providing people who inject drugs (PWID) with naloxone is essential to preventing deaths. However, research regarding gaps in naloxone delivery is limited.

METHODS

We interviewed 536 PWID in San Francisco and Los Angeles, California from 2017 to 2018. We described naloxone engagement and re-engagement cascades, and identified factors associated with receiving naloxone in the past six months and currently owning naloxone.

RESULTS

The engagement cascade showed 72 % of PWID ever received naloxone, 49 % received it in the past six months, and 35 % currently owned naloxone. The re-engagement cascade showed, among PWID who received naloxone in the past six months, 74 % used and/or lost naloxone, and 67 % refilled naloxone. In multivariable analyses, identifying as Latinx (aRR = 0.53; 95 % CI: 0.39, 0.72) and Black (aRR = 0.73; 95 % CI: 0.57, 0.94) vs White were negatively associated with receiving naloxone in the past six months, while using opioids 1-29 times (aRR = 1.35; 95 % CI: 1.04, 1.75) and 30+ times (aRR = 1.52; 95 % CI: 1.17, 1.99) vs zero times in the past 30 days and witnessing an overdose in the past six months (aRR = 1.69; 95 % CI: 1.37, 2.08) were positively associated with receiving naloxone in the past six months. In multivariable analyses, being unhoused vs housed (aRR = 0.82; 95 % CI: 0.68, 0.99) was negatively associated with currently owning naloxone.

CONCLUSIONS

Our study adds to the literature by developing naloxone engagement and re-engagement cascades to identify disparities. Naloxone scale-up should engage populations facing inequitable access, including people of color and those experiencing homelessness.

The impact of current opioid agonist therapy on hepatitis C virus treatment initiation among people who use drugs from in the DAA era: A population-based study

BACKGROUND

Evidence that opioid agonist therapy (OAT) is associated with increased odds of hepatitis C virus (HCV) treatment initiation among people who use drugs (PWUD) is emerging. The objective of this study was to determine the association between current OAT and HCV treatment initiation among PWUD in a population-level linked administrative dataset.

METHODS

The British Columbia (BC) Hepatitis Testers Cohort was used for this study, which includes all people tested for or diagnosed with HCV in BC, linked to medical visits, hospitalizations, laboratory, prescription drug, and mortality data from 1992 until 2019. PWUD with injecting drug use or opioid use disorder and chronic HCV infection were identified for inclusion in this study. HCV treatment initiation was the main outcome, and subdistribution proportional hazards modeling was used to assess the relationship with current OAT.

RESULTS

13,803 PWUD with chronic HCV were included in this study. Among those currently on OAT at the end of the study period, 47% (2,704/5,770) had started HCV treatment, whereas 22% (1778/8033) of those not currently on OAT has started HCV treatment .. Among PWUD with chronic HCV infection, current OAT was associated with higher likelihood of HCV treatment initiation in time to event analysis (adjusted hazard ratio 1.84 [95%CI, 1.50, 2.26]).

CONCLUSIONS

Current OAT was associated with a higher likelihood of HCV treatment initiation. However, many PWUD with HCV currently receiving OAT have yet to receive HCV treatment. Enhanced integration between substance use care and HCV treatment is needed to improve the overall health of PWUD.

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.

Quantifying opioid use disorder Cascade of Care outcomes in an American Indian tribal nation in Minnesota

American Indian communities in Minnesota have been disproportionately impacted by the opioid use disorder (OUD) epidemic, which tribal communities have taken numerous steps to address. The Cascade of Care is a public health framework for measuring population-level OUD risk, treatment engagement, treatment retention, and recovery outcomes, which can help communities monitor the impact of responses to the OUD epidemic and identify where treatment- and recovery-related barriers and facilitators may exist. However, no studies have quantified the Cascade of Care stages within tribal communities and the extent to which these stages can be quantified using existing data sources is unknown. We utilized data from the Minnesota Drug and Alcohol Abuse Normative Evaluation System (DAANES) to quantify OUD Cascade of Care stages for an American Indian tribal nation in Minnesota and for the entire state. DAANES data indicated 269 individuals in the tribal community received treatment for opioid-related problems in 2018. Among them, an estimated 65-99 % initiated medications for OUD and an estimated 13-41 % were retained in treatment for at least 180 days. Existing state-level data can provide information about Cascade of Care stages for American Indian communities, particularly with regard to treatment admission, initiation of medications for OUD, and treatment retention. Additional data sources are needed to measure population-level OUD risk, recovery, and cultural and contextual factors that may impact treatment and recovery.

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%).

Diagnosis of Opioid Use Disorder by Youths Assessed in Acute Care Settings in British Columbia, Canada

OBJECTIVES

To describe trends in the number of youths diagnosed with opioid use disorder (OUD) and to identify factors associated with OUD diagnosis in acute care settings.

STUDY DESIGN

Data from a population-based retrospective cohort study with linkage of 6 health administrative databases for 13 009 youth age 12-24 years identified with OUD between 2001 and 2018 in British Columbia, Canada were used to describe annual diagnoses. Using a multiple logistic regression model, we estimated the association between past-year health care utilization and OUD diagnosis in acute settings, controlling for sociodemographic and OUD-related comorbid conditions.

RESULTS

Annual OUD diagnoses quadrupled between 2003 and 2017 (from 326 to 1473). Among the 6579 youth diagnosed with OUD between April 1, 2013 and September 30, 2018, 88.1% had past-year health system contacts. Youth age 12-18 had higher odds of OUD diagnosis in acute care (aOR 2.04; 95% CI 1.78, 2.34). Compared with no health care contact, youth receiving outpatient care only were less likely to be diagnosed with OUD in acute care (aOR 0.69; 95% CI 0.56, 0.84) and those with >1 urgent hospitalization were more likely to be diagnosed with OUD in acute care (aOR 1.87; 95% CI 1.40,2.49).

CONCLUSIONS

More than 88% of youth had past-year health system contacts prior to diagnosis. Those age 12-18 years and with urgent hospitalizations in the year prior to diagnosis were more likely to have OUD diagnosed in acute care settings. Establishing an effective evidence-based system for early detection and intervention among youth with OUD must be a priority.

The cascade of care for opioid use disorder among youth in British Columbia, 2018

BACKGROUND

Medication for opioid use disorder (MOUD) is associated with substantial reductions in the risk of mortality, and American and Canadian guidelines recommend it as part of the full range of available treatments for youth with opioid use disorder (OUD). We estimated the OUD cascade of care for all adolescents (ages 12-18) and young adults (19-24) with OUD in British Columbia, Canada (BC) in 2018.

METHODS

Using a provincial-level linkage of six health administrative databases, we classified youth with OUD as adolescents (ages 12-18) or young adults (19-24) to compare with older adults (≥25) and described key factors known to influence engagement in health care. The eight-stage cascade of care included diagnosed with OUD, ever engaged in MOUD, recently in MOUD, currently in MOUD, and retained in MOUD for ≥1 month, ≥3 months, ≥12 months, ≥24 months.

RESULTS

We identified 4048 youth diagnosed with OUD as of September 30, 2018 (6.3% of all people with OUD). Most were young adults, aged 19-24 (n = 3602; 89.0% of all youth), a majority of whom were males (n = 1984; 55.1%). In contrast, adolescents diagnosed with OUD (n = 446; 11.0% of all youth) were mostly females (n = 287; 64.4%). Compared to adolescents, there were more young adults diagnosed with OUD ever engaged in MOUD (71.4% v. 36.5%), currently on MOUD (29.3% v. 16.8%), and retained in care for ≥1 year (8.6% v. 2.0%).

CONCLUSIONS

A high proportion of youth aged 12-24 diagnosed with OUD in a health care setting in British Columbia received MOUD yet continued engagement is infrequent, particularly for adolescents. Long-term treatment plans for youth need to consider including MOUD when appropriate as part of tailored, youth-friendly services.

Estimates of opioid use disorder prevalence from a regression-based multi-sample stratified capture-recapture analysis

BACKGROUND

An epidemic of opioid overdose has spread across North America, with illicit drug-related overdose emerging as a leading cause of death in recent years. Estimates of opioid use disorder (OUD) prevalence at the level of the public health service delivery area are needed to project resource needs and identify priority areas for targeted intervention. Our objective is to estimate the annual prevalence of OUD in British Columbia (BC), Canada, from 2000 to 2017.

METHODS

We performed a multi-sample stratified capture-recapture analysis to estimate OUD prevalence in BC. The analysis included individuals identified from 3 administrative databases for 2000-2011 and 4 databases for 2012-2017, linked at the individual level. Negative binomial regression models on the counts of individuals within these strata were used to estimate prevalence, adjusting for dependency between databases.

RESULTS

OUD prevalence in BC among people aged 12 years or older was 1.00 % (N = 34,663 individuals) in 2000 and increased to 1.54 % (N = 61,080) in 2011. Between 2013 and 2017 prevalence increased from 1.57 % (95 % confidence interval: 1.56-1.58) to 1.92 % (1.89-1.95; N = 83,760; 82,492-84,855). The greatest increases in prevalence were observed among males 12-30 years old and 31-44 years old, with 43.2 % and 40.2 % increases from 2013 to 2017.

CONCLUSIONS

In BC, the OUD prevalence was 1.92 % among people 12 years or older in 2017. We estimated that prevalence has nearly doubled since 2000, with the highest increases in prevalence observed among males under 45.

The Causal Effect of Opioid Agonist Treatment on Adherence to Direct-Acting Antiviral Treatment for Hepatitis C Virus

Background

Opioid agonist treatment (OAT) supports adherence in medication regimens for other concurrent conditions. However, sparse evidence is available on its effect on promoting retention to direct-acting antivirals (DAAs) for people with opioid use disorder (PWOUD) with concurrent hepatitis C virus (HCV). Our objective was to determine the causal impact of OAT exposure on DAA adherence among HCV-positive PWOUD.

Methods

We executed a retrospective study using linked population-level data for British Columbia, Canada (January 1996–September 2018). We estimated the effect of OAT on DAA adherence using generalized estimating equations (GEEs) and marginal structural modeling (MSM) for time-varying confounding. The primary outcome was 85% DAA adherence (minimum 6 of 7 days).

Results

We included 2820 HCV-positive PWOUD who initiated a DAA regimen (32.6% female, 83.9% previously accessing OAT), with 2410 (95% among uncensored episodes) completing the regimen. The GEE-adjusted odds ratio of DAA adherence after OAT exposure was 1.05 (0.89–1.23), whereas the MSM-adjusted odds ratio was 0.97 (0.78–1.22).

Conclusions

In a setting with universal healthcare and widespread access to OAT and DAA treatment, DAA regimen completion rates were high regardless of OAT, and engagement in OAT did not increase DAA adherence. Nonengagement in OAT should not preclude DAA treatment for PWOUD.

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.