Trends and sex differences in prescription opioid deaths in British Columbia, Canada

Development of prescribing indicators related to opioid-related harm in patients with chronic pain in primary care-a modified e-Delphi study

BACKGROUND

Long-term opioid use is associated with dependency, addiction, and serious adverse events. Although a framework to reduce inappropriate opioid prescribing exists, there is no consensus on prescribing indicators for preventable opioid-related problems in patients with chronic pain in primary care in the UK. This study aimed to identify opioid prescription scenarios for developing indicators for prescribing opioids to patients with chronic pain in primary care.

METHODS

Scenarios of opioid prescribing indicators were identified from a literature review, guidelines, and government reports. Twenty-one indicators were identified and presented in various opioid scenarios concerning opioid-related harm and adverse effects, drug-drug interactions, and drug-disease interactions in certain disease conditions. After receiving ethics approval, two rounds of electronic Delphi panel technique surveys were conducted with 24 expert panellists from the UK (clinicians, pharmacists, and independent prescribers) from August 2020 to February 2021. Each indicator was rated on a 1-9 scale from inappropriate to appropriate. The score's median, 30th and 70th percentiles, and disagreement index were calculated.

RESULTS

The panel unanimously agreed that 15 out of the 21 opioid prescribing scenarios were inappropriate, primarily due to their potential for causing harm to patients. This consensus was reflected in the low appropriateness scores (median ranging from 1 to 3). There were no scenarios with a high consensus that prescribing was appropriate. The indicators were considered inappropriate due to drug-disease interactions (n = 8), drug-drug interactions (n = 2), adverse effects (n = 3), and prescribed dose and duration (n = 2). Examples included prescribing opioids during pregnancy, concurrently with benzodiazepines, long-term without a laxative prescription and prescribing > 120-mg morphine milligram equivalent per day or long-term duration over 3 months after surgery.

CONCLUSIONS

The high agreement on opioid prescribing indicators indicates that these potentially hazardous consequences are relevant and concerning to healthcare practitioners. Future research is needed to evaluate the feasibility and implementation of these indicators within primary care settings. This research will provide valuable insights and evidence to support opioid prescribing and deprescribing strategies. Moreover, the findings will be crucial in informing primary care practitioners and shaping quality outcome frameworks and other initiatives to enhance the safety and quality of care in primary care settings.

Longitudinal Trajectory of Opioid Prescribing and its Associated Serious Adverse Events: A Population-Wide Cohort Study in Taiwan

Chronic opioid prescribing (COP) for noncancer pain is highly restricted in Taiwan, but tramadol is not listed in the regulation on chronic prescribing. This study investigated the trajectories of COP in noncancer pain when considering tramadol in Taiwan and identified the risk of serious adverse events. This population-wide longitudinal cohort study used the Taiwan National Health Insurance claims records from 2001 to 2016. Adults prescribed opioids (including tramadol) and without cancer were selected. Patients who received COP (opioid supply days for 28 days or continuous opioid supply for 14 days) in the first patient quarter were included, and serious adverse events were identified. Group-based trajectory models were applied to identify patients with a similar trajectory of quarterly COP. The Cox proportional hazard model was applied to assess the association between adverse events and patients' trajectories. Of the 2,360,358 noncancer opioid users, 476,934 (20.2%) received COP in the first quarter. Four groups of COP trajectory were identified, and 59,310 (12.8%) patients received COP quarterly over 2 years. Patients categorized into the trajectory of long-term COP had a significantly higher crude incidence rate of cardiovascular death, seizure, and hypoglycemia. Still, there is no newly developed opioid use disorder. There was a substantial underestimate in COP in Taiwan when tramadol was not considered. Notably, 10% of them could receive COP for over 2 years. The result raises concern about unmet pain management needs and the limited accessibility of alternative treatments for noncancer pain.

Feasibility and validity of using healthcare databases to conduct cross-national comparative studies of opioid use, its determinants and consequences

PURPOSE

A cross-national comparative (CNC) study about opioid utilization would allow the identification of strategies to improve pain management and mitigate risk. However, little is known about the accessibility and validity of information in healthcare databases internationally. This study aimed to identify the feasibility of using healthcare databases to conduct a CNC study of opioid utilization and its associated consequences.

METHODS

A cross-sectional survey was launched in March 2018, including experts interested in CNC studies comparing opioid utilization by purposeful sampling. An electronic survey was used to collect database characteristics, medicine information, and linkage information of each aggregate-level dataset (AD) and individual patient-level dataset (IPD).

RESULTS

Overall, participants from 21 geographical regions reported 18 ADs and 19 IPDs. Information on dispensed medications is available from 17 ADs and 17 IPDs. Of the 16 ADs that include primary care settings, only 9 ADs can obtain information from secondary care settings. Fourteen IPDs included patients' characteristics or could be retrieved from linkage databases. Although most ADs are publicly accessible (n = 13), only five IPDs can be accessed without extra cost.

CONCLUSION

Most ADs could be used to report opioid utilization in a primary care setting. IPDs with linkage databases should be applied to identify potential determinants, clinical outcomes, and policy impact. Data access restrictions and governance policies across jurisdictions can be challenging for timely analysis and require further collaboration.

Identifying the changing age distribution of opioid-related mortality with high-frequency data

Background

Opioid-related mortality continues to rise across North America, and mortality rates have been further exacerbated by the COVID-19 pandemic. This study sought to provide an updated picture of trends of opioid-related mortality for Ontario, Canada between January 2003 and December 2020, in relation to age and sex.

Methods

Using mortality data from the Office of the Chief Coroner for Ontario, we applied Bayesian Poisson regression to model age/sex mortality per 100,000 person-years, including random walks to flexibly capture age and time effects. Models were also used to explore how trends might continue into 2022, considering both pre- and post-COVID-19 courses.

Results

From 2003 to 2020, there were 11,633 opioid-related deaths in Ontario. A shift in the age distribution of mortality was observed, with the greatest mortality rates now among younger individuals. In 2003, mortality rates reached maximums at 5.5 deaths per 100,000 person-years (95% credible interval: 4.0–7.6) for males around age 44 and 2.2 deaths per 100,000 person-years (95% CI: 1.5–3.2) for females around age 51. As of 2020, rates have reached maximums at 67.2 deaths per 100,000 person-years (95% CI: 55.3–81.5) for males around age 35 and 16.8 deaths per 100,000 person-years (95% CI: 12.8–22.0) for females around age 37. Our models estimate that opioid-related mortality among the younger population will continue to grow, and that current conditions could lead to male mortality rates that are more than quadruple those of pre-pandemic estimations.

Conclusions

This analysis may inform a refocusing of public health strategy for reducing rising rates of opioid-related mortality, including effectively reaching both older and younger males, as well as young females, with health and social supports such as treatment and harm reduction measures.

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.

National trends in population rates of opioid-related mortality, hospitalization and emergency department visits in Canada between 2000 and 2017. A population-based study

BACKGROUND AND AIMS

Existing assessments of the time-trends of opioid-related mortality, hospitalization and emergency department visits in Canada have relied mainly on provincial databases, while national assessments generally do not provide information before 2016. We aimed to estimate Canadian national time trends in opioid-related mortality from 2000 to 2017 and opioid-related hospitalization and emergency department visits between 2000 and 2012.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Residents of all Canadian provinces and territories for which comparable data were available from 2000 to 2017.

MEASUREMENTS

We identified opioid-related mortality, hospitalization and emergency department visits using validated algorithms using ICD codes from administrative databases. We calculated crude rates and sex- and age-adjusted rates per million. For hospitalizations, we calculated case-fatality, 90-day and 365-day all-cause mortality and opioid-related re-hospitalization rates. We used Poisson regression to examine the significance of the time trend.

FINDINGS

From 2000 to 2017, the adjusted opioid mortality rate in Canada (outside Quebec) increased significantly by 592.9% (from 20.0 opioid deaths per million in 2000 to 118.3 in 2017). The highest year-to-year increases were from 2015 to 2016 (31.8%) and from 2016 to 2017 (52.2%). The adjusted hospitalizations doubled significantly during the study period (an increase of 103.7%, from 159.7 opioid hospitalizations per million Canadians in 2000 to 325.3 in 2012). The adjusted rate of emergency department visits increased significantly by 188.7% (from 280.6 per million in 2000 to 810.1 in 2012). Case-fatality was 2.3% overall and was mainly constant during the study period. Both 90- and 365-day all-cause mortality increased significantly between 2000 and 2011 (from 1.7 to 3.1% and 3.9 to 7.4%, respectively), while re-hospitalization for opioid-related diagnoses was reduced (from 7.8 to 6.4% and 14.2 to 12.9%, respectively).

CONCLUSIONS

Opioid-related mortality, hospitalization and emergency department visits in Canada have been increasing gradually since 2000.

Opioids and Gabapentinoids Utilisation and Their Related-Mortality Trends in the United Kingdom Primary Care Setting, 2010-2019: A Cross-National, Population-Based Comparison Study

Background: There is growing concern over the increasing utilisation trends of opioids and gabapentinoids across but there is lack of data assessing and comparing the utilisation trends across the four United Kingdom countries. We assessed/compared opioids and gabapentinoids utilisation trends across the four United Kingdom countries then evaluated the correlation between their utilisation with related mortality.

Methods: This repeated cross-national study used Prescription Cost Analysis (PCA) datasets (2010–2019). Opioids and gabapentinoids utilisation were measured using number of items dispensed/1,000 inhabitants and defined daily doses (DDDs)/1,000 inhabitant/day. Number of Opioids and gabapentinoids-related mortality were extracted from the United Kingdom Office for National Statistics (2010–2018). Data were analysed using descriptive statistics including linear trend analysis; correlation between the Opioids and gabapentinoids utilisation and their related mortality using Pearson correlation coefficient.

Results: The results illustrated an overall significant increasing trend in the utilisation of opioids (12.5–14%) and gabapentinoids (205–207%) with substantial variations among the four United Kingdom countries. For opioids, Scotland had the highest level of number of items dispensed/1,000 inhabitant (156.6% higher compared to the lowest level in England), whereas in terms of DDD/1,000 inhabitant/day, NI had the highest level. Utilisation trends increased significantly across the four countries ranging from 7.7% in Scotland to 20.5% in NI (p < 0.001). Similarly, for gabapentinoids, there were significant increasing trends ranging from 126.5 to 114.9% in NI to 285.8–299.6% in Wales (p < 0.001) for number of items/1,000 inhabitants and DDD/1,000 inhabitant/day, respectively. Although the utilisation trends levelled off after 2016, this was not translated into comparable reduction in opioids and gabapentinoids-related mortality as the latter continued to increase with the highest level in Scotland (3.5 times more deaths in 2018 compared to England- 280.1 vs. 79.3 deaths/million inhabitants). There were significant moderate-strong positive correlations between opioids and gabapentinoids utilisation trends and their related mortality.

Conclusion: The utilisation trends of opioids and gabapentinoids have increased significantly with substantial variations among the four United Kingdom countries. This coincided with significant increase in their related mortality. Our findings support the call for immediate actions including radical changes in official United Kingdom policies on drug use and effective strategies to promote best clinical practice in opioids and gabapentinoids prescribing.

Association between opioid-related deaths and persistent opioid prescribing in primary care in England: a nested case-control study

AIM

This study aimed to evaluate the association between opioid-related deaths and persistent opioid utilisation in the United Kingdom (UK).

METHODS

This nested case-control study used the UK Clinical Practice Research Datalink, linking the Office for National Statistics death registration. Adult opioid users with recorded opioid-related death between 2000 and 2015 were included and matched to four opioid users (controls) based on a disease risk score. Persistent opioid utilisation (opioid prescriptions ≥3 quarters/year and oral morphine equivalent dose ≥4500 mg/year) and psychotropic prescriptions were identified annually during the three patient-years before the date of opioid-related death. Conditional logistic regression was used to assess the association between persistent opioid utilisation and opioid-related death, and the results were reported as adjusted odds ratios (aOR) and 95% confidence intervals (95%CI).

RESULTS

Of the 902,149 opioid users, 230 opioid-related deaths (cases) and 920 controls were identified. Persistent opioid utilisation was significantly associated with an increased risk of opioid-related deaths (aOR: 1.9; 95%CI: 1.2, 2.9) when persistent opioid utilisation was defined by both annual dose and number of quarters. Concurrent prescription of opioids and tricyclic antidepressants (aOR: 2.0; 95%CI: 1.2, 3.5) or higher dose of benzodiazepine (aOR: 6.5; 95%CI: 4.0, 10.4) or gabapentinoids (aOR: 6.2; 95%CI: 2.9, 13.5) were associated with opioid-related death.

CONCLUSION

Persistent opioid prescribing and concurrent prescribing of psychotropics were associated with a higher risk of opioid-related death and should be avoided in clinical practice. An evidence-based indicator to monitor the safety of prescribed opioids during opioid de-prescribing is needed.

Effectiveness of micro-induction approaches to buprenorphine initiation: A systematic review protocol

BACKGROUND

Buprenorphine is first-line opioid agonist therapy for opioid use disorder. Standard regimens require that patients be in opioid withdrawal prior to induction, which is a barrier for many. Micro-induction is a novel induction approach that does not require patients to be in withdrawal. Our primary objective is to synthesize available evidence on the effectiveness of micro-inductions on patient and clinical outcomes compared to standard dosing or other approaches, or evaluated without a comparator group. Secondary objectives are to synthesize evidence on clinical factors that influence micro-induction effectiveness, and to summarize micro-induction regimens described in the literature.

METHODS

We will search MEDLINE, Embase, CINAHL, Psycinfo, Science Citation Index, and the grey literature for studies that include adolescents or adults with opioid use disorder who received a buprenorphine micro-induction regimen. We will consider any patient or clinical outcomes defined by study authors. We will include controlled and non-controlled interventional studies, observational studies, case reports/series and reports from relevant organizations or guidelines pertinent to our third objective. We will select studies, extract data and assess study quality (using the Downs and Black, and Cochrane Risk of Bias tools) in duplicate. We will narratively synthesize our results, and will meta-analyze outcome measures if multiple studies report common outcomes with acceptably low heterogeneity.

DISCUSSION

Our review will include the most up-to-date available data on buprenorphine micro-inductions. We anticipate limitations relating to study heterogeneity and quality. We will disseminate study results widely to inform updated guidelines for opioid agonist therapy prescribers.

Recent changes in trends of opioid overdose deaths in North America

Background

As several regulatory and environmental changes have occurred in North America, trends in overdose deaths were examined in the United States (US), Ontario and British Columbia (BC), including changes in consumption levels of prescription opioids (PO) and overdose deaths, changes in correlations between consumption levels of PO and overdose deaths and modeled differences between observed and predicted overdose deaths if no changes had occurred.

Methods

Consumption levels of PO included defined daily doses for statistical purposes per million inhabitants per day for the US and Canada (2001–2015). Overdose deaths included opioid overdose deaths for the US (2001–2017) and Ontario (2003–2017) and illicit drug overdose deaths for BC (2001–2017). The analytic techniques included structural break point analyses, Pearson product-moment correlations and multivariate Gaussian state space modeling.

Results

Consumption levels of PO changed in the US in 2010 and in Canada in 2012. Overdose deaths changed in the US in 2014 and in Ontario and BC in 2015. Prior to the observed changes in consumption levels of PO, there were positive correlations between consumption levels of PO and overdose deaths in the US (r = 0.99, p < 0.001) and Ontario (r = 0.92, p = 0.003). After the observed changes in consumption levels of PO, there was a negative correlation between consumption levels of PO and overdose deaths in the US (r = − 0.99, p = 0.002). Observed overdose deaths exceeded predicted overdose deaths by 5.7 (95% Confidence Interval [CI]: 4.8–6.6), 3.5 (95% CI: 3.2–3.8) and 21.8 (95% CI: 18.6–24.9) deaths per 100,000 people in the US, Ontario and BC, respectively in 2017. These excess deaths corresponded to 37.7% (95% CI: 31.9–43.6), 39.2% (95% CI: 36.3–42.1) and 72.2% (95% CI: 61.8–82.6) of observed overdose deaths in the US, Ontario and BC, respectively in 2017.

Conclusions

The opioid crisis has evolved in North America, as a sizeable proportion of overdose deaths are now attributable to the several regulatory and environmental changes. These findings necessitate substance use policies to be conceptualized more broadly as well as the continued expansion of harm reduction services and types of pharmacotherapy interventions.

A decade of extreme oscillations in opioid control and availability: implications for public health in a Canadian setting

We comment on developments in and impacts of medical opioid control and availability in the province of British Columbia (Canada). Population-level dispensing of (strong) prescription opioids doubled in 2005-2011, yet subsequently declined by half 2011-2018 following implementation of various opioid control measures. Notwithstanding this inversion, BC has featured the highest population rates of opioid-related mortality and morbidity in Canada. The erratic opioid availability patterns presumably facilitated major increases in opioid misuse, morbidity, and mortality. Tangible benefits for pain care from increased medical opioid availability remain un-evidenced. Rather, recent decreases in medical opioid dispensing have not been matched by equivalent reductions in demand for (non-)medical use yet have coincided with widespread proliferation of toxic, illicit opioid supply and related major increases in opioid-related mortality. These developments appear to have undermined rather than benefitted public health and offer a poignant case study in ineffective psychotropic drug control and public health policy towards preventing similar experiences elsewhere.

Prescription opioids: Regional variation and socioeconomic status - evidence from primary care in England

BACKGROUND

This study aimed to quantify opioid prescriptions dispensed from primary care practices throughout England and investigate its association with socioeconomic status (SES).

METHODS

This cross-sectional study used publicly available data in 2015, including practice-level dispensing data and characteristics of registrants from the United Kingdom (UK) National Health Service Digital, and Index of Multiple Deprivation (IMD) data from Department of Communities and Local Government. Practices in England which issued opioid prescriptions that could be assigned a defined daily dose (DDD) in the claim-based dispensing database were included. The total amount of opioid prescriptions dispensed (DDD/1000 registrants/day) was calculated for each practice. The association between dispensed opioid prescriptions and IMD was analyzed by multi-level regression and adjusted for registrants' characteristics and the clustered effect of Clinical Commissioning Groups. Subgroup analysis was conducted for practices in London, Birmingham, Manchester and Newcastle.

RESULTS

Of the 7856 included practices in England, the median and interquartile range (IQR) of prescription opioids dispensed was 36.9 (IQR: 23.1, 52.5) DDD/1000 registrants/day. The median opioid utilization (DDD/1000 registrants/day) amongst practices varied between Manchester (53.1; IQR: 36.8, 71.4), Newcastle (48.9; IQR: 38.8, 60.1), Birmingham (35.3; IQR: 23.1, 49.4) and London (13.9; IQR: 8.1, 18.8). Lower SES, increased prevalence of patients aged more than 65 years, female gender, smoking, obesity and depression were significantly associated with increased opioid prescriptions. For every decrease in IMD decile (lower SES), there was a significant increase of opioid utilization by 1.0 (95% confidence interval: 0.89, 1.2, P < 0.001) DDD/1000 registrants/day.

CONCLUSION

There was substantial variation in opioid prescriptions among practices from Northern and Eastern England to Southern England. A significant association between increased opioid prescriptions and greater deprivation at a population level was observed. Further longitudinal studies using individual patient data are needed to validate this association and identify the potential mechanisms.

Development and characteristics of the Provincial Overdose Cohort in British Columbia, Canada

Introduction

British Columbia (BC), Canada declared a public health emergency in April 2016 for opioid overdose. Comprehensive data was needed to identify risk factors, inform interventions, and evaluate response actions. We describe the development of an overdose cohort, including linkage strategy, case definitions, and data governance model, and present the resulting characteristics, including data linkage yields and case overlap among data sources.

Methods

Overdose events from hospital admissions, physician visits, poison centre and ambulance calls, emergency department visits, and coroner’s data were grouped into episodes if records were present in multiple sources. A minimum of five years of universal health care records (all prescription dispensations, fee-for-service physician billings, emergency department visits and hospitalizations) were appended for each individual. A 20% random sample of BC residents and a 1:5 matched case-control set were generated. Consultation and prioritization ensured analysts worked to address questions to directly inform public health actions.

Results

10,456 individuals suffered 14,292 overdoses from January 1, 2015 to Nov 30, 2016. Only 28% of overdose events were found in more than one dataset with the unique contribution of cases highest from ambulance records (32%). Compared with fatal overdoses, non-fatal events more often involved females, younger individuals (20 to 29 years) and those 60 or older. In 78% of illegal drug deaths, there was no associated ambulance response. In the year prior to first recorded overdose, 60% of individuals had at least one ED visit, 31% at least one hospital admission, 80% at least one physician visit, and 87% had filled at least one prescription in a community pharmacy.

Conclusion

While resource-intensive to establish, a linked cohort is useful for characterizing the full extent of the epidemic, defining sub-populations at risk, and patterns of contact with the health system. Overdose studies in other jurisdictions should consider the inclusion of multiple data sources.

Comparing the contribution of prescribed opioids to opioid-related hospitalizations across Canada: A multi-jurisdictional cross-sectional study

BACKGROUND

The Canadian opioid crisis is a complex, multifaceted problem involving prescribed, diverted and illicitly manufactured opioids. This study sought to characterize the contribution of prescribed opioids to opioid-related hospitalizations in Canada.

METHODS

We conducted a cross-sectional study of all individuals who were admitted to hospital for opioid toxicity in British Columbia (BC), Manitoba and Ontario between April 2015 and March 2016. We used prescription claims to ascertain active prescription opioid use at time of hospital admission. In secondary analyses, we defined recent opioid prescriptions as those that were dispensed in the 30 and 180 days up to and including admission, and the prevalence of active co-prescription of benzodiazepines with opioids at time of overdose.

RESULTS

We identified 2599 instances of opioid toxicity over the study period. In BC, 34.1% of hospital visits for overdose occurred in people with an active opioid prescription, compared to 52.2% (47 of 90) in Manitoba and 52.8% (804 of 1524) in Ontario. However, active opioid prescriptions prior to overdose varied significantly by age and sex. Co-prescription of opioids and benzodiazepines prior to overdose ranged from 17.1% in BC to 35.6% in Manitoba.

CONCLUSIONS

There remains an important ongoing contribution of prescribed opioids to overdoses across Canada, but non-prescribed opioids play a growing role, particularly in BC. These findings underscore the importance of more judicious opioid prescribing, harm reduction programs, and improved access to addiction care for people with an opioid use disorder.

Increasing diversion of methadone in Vancouver, Canada, 2005-2015

BACKGROUND AND AIM

Although methadone, an opioid agonist, has been an effective medication used to treat opioid use disorder for over 40years, recent studies have found that methadone was identified in more than a quarter of prescription opioid-related deaths among people who use illicit drugs in Vancouver, Canada. Thus, we sought to longitudinally examine the availability of diverted methadone among people who inject drugs (PWID).

DESIGN AND METHODS

Data were collected from three prospective cohorts of PWID in Vancouver, Canada between December 2005 and May 2015. Multivariable generalized estimating equation logistic regression was used to identify temporal trends in the immediate availability of diverted methadone (defined as the ability to acquire illicit methadone in <10min).

RESULTS

A total of 2092 participants, including 727 (34.8%) women, were included in the present study. In the multivariable analyses after adjusting for a range of potential confounders, later calendar year (adjusted odds ratio [AOR]=1.21 per year; 95% confidence interval [CI]: 1.19-1.23) was independently and positively associated with reporting immediate availability of diverted methadone.

CONCLUSIONS

We observed a significant increase in the reported availability of diverted methadone among PWID over a ten-year follow-up period. Further research is needed to identify strategies to limit methadone diversion and assess the impact of alternative medications that are equally effective but safer, such as buprenorphine/naloxone.

The State of Opioid Agonist Therapy in Canada 20 Years after Federal Oversight

Opioid agonist therapy was introduced in Canada in 1959 with the use of methadone for the treatment of opioid dependence. The regulation of methadone was the responsibility of Health Canada until 1995, when oversight was transferred to the provincial health systems. During the more than 20 years since the federal health authority transferred oversight of methadone to the provincial level, methadone programming has evolved differently in every province. The landscape of opioid dependence treatment is varied across the country, with generally increasing treatment capacity in all provinces and dramatic increases in some. Each province has an independent methadone program with differing policies, contingency management strategies, laboratory monitoring policies, and delivery methods. Treatment options have increased, with buprenorphine- and heroin-assisted treatment becoming available to limited degrees. Despite this, access remains a challenge in many parts of the country (particularly rural and remote areas) because the demand for treatment has increased even more rapidly than the capacity. Although treatment access remains a priority in many jurisdictions, there is also a need to attend to treatment quality as treatment access expands, including integration with addiction counselling, primary care, and mental health care. As well, coordinated monitoring and reporting of treatment need, quality, and delivery are required; implementing a national policy to promote planning would have tremendous value.