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.

Influence of physician networks on the implementation of pharmaceutical alternatives to a toxic drug supply in British Columbia.

BACKGROUND: Characterizing the diffusion of adopted changes in policy and clinical practice can inform enhanced implementation strategies to ensure prompt uptake in public health emergencies and other rapidly evolving disease areas. A novel guidance document was introduced at the onset of the COVID-19 pandemic in British Columbia (BC), Canada, which supported clinicians to prescribe opioids, stimulants, and benzodiazepines. We aimed to determine the extent to which uptake and discontinuation of an initial attempt at a prescribed safer supply (PSS) program were influenced through networks of prescribers. METHODS: We executed a retrospective population-based study using linked health administrative data that captured all clinicians who prescribed to at least one client with a substance use disorder from March 27, 2020, to August 31, 2021. Our main exposure was the prescribing patterns of an individuals' peers, defined as the proportion of a prescribers' professional network (based on shared clients), which had previously prescribed PSS, updated monthly. The primary outcome measured whether a clinician had prescribed their initial PSS prescription during a given calendar month. The secondary outcome was the discontinuation of PSS prescribing, defined as an absence for PSS prescriptions for at least 3 months. We estimated logistic regression models using generalized estimated equations on monthly repeated measurements to determine and characterize the extent to which peer networks influenced the initiation and discontinuation of PSS prescribing, controlling for network, clinician, and caseload characteristics. Innovators were defined as individuals initiating PSS prior to May 2020, and early adopters were individuals initiating PSS after. RESULTS: Among 14,137 prescribers treating clients with substance use disorder, there were 228 innovators of prescribed safer supply and 1062 early adopters through the end of study follow-up, but 653 (50.6%) were no longer prescribing by August 2021. Prescribers with over 20% of peers whom had adopted PSS had a nearly fourfold higher adjusted odds of PSS prescribing themselves (aOR: 3.79, 95% CI: (3.15, 4.56)), compared to those with no connected safer supply prescribers. CONCLUSIONS: The uptake of PSS in BC was highly dependent on the behavior of prescribers' peer networks. Future implementation strategies to support PSS or other policies would benefit from leveraging networks of prescribers.

Opioid Coprescription Through Risk Mitigation Guidance and Opioid Agonist Treatment Receipt.

Importance: At the onset of the COVID-19 pandemic, the government of British Columbia, Canada, released clinical guidance to support physicians and nurse practitioners in prescribing pharmaceutical alternatives to the toxic drug supply. These alternatives included opioids and other medications under the risk mitigation guidance (RMG), a limited form of prescribed safer supply, designed to reduce the risk of SARS-CoV-2 infection and harms associated with illicit drug use. Many clinicians chose to coprescribe opioid medications under RMG alongside opioid agonist treatment (OAT). Objective: To examine whether prescription of hydromorphone tablets or sustained-release oral morphine (opioid RMG) and OAT coprescription compared with OAT alone is associated with subsequent OAT receipt. Design, Setting, and Participants: This population-based, retrospective cohort study was conducted from March 27, 2020, to August 31, 2021, included individuals from 10 linked health administrative databases from British Columbia, Canada. Individuals who were receiving OAT at opioid RMG initiation and individuals who were receiving OAT and eligible but unexposed to opioid RMG were propensity score matched at opioid RMG initiation on sociodemographic and clinical variables. Data were analyzed between January 2023 and February 2024. Exposure: Opioid RMG receipt (≥4 days, 1-3 days, or 0 days of opioid RMG dispensed) in a given week. Main Outcome and Measures: The main outcome was OAT receipt, defined as at least 1 dispensed dose of OAT in the subsequent week. A marginal structural modeling approach was used to control for potential time-varying confounding. Results: A total of 4636 individuals (2955 [64%] male; median age, 38 [31-47] years after matching) were receiving OAT at the time of first opioid RMG dispensation (2281 receiving ongoing OAT and 2352 initiating RMG and OAT concurrently). Opioid RMG receipt of 1 to 3 days in a given week increased the probability of OAT receipt by 27% in the subsequent week (adjusted risk ratio, 1.27; 95% CI, 1.25-1.30), whereas receipt of opioid RMG for 4 days or more resulted in a 46% increase in the probability of OAT receipt in the subsequent week (adjusted risk ratio, 1.46; 95% CI, 1.43-1.49) compared with those not receiving opioid RMG. The biological gradient was robust to different exposure classifications, and the association was stronger among those initiating opioid RMG and OAT concurrently. Conclusions and Relevance: This cohort study, which acknowledged the intermittent use of both medications, demonstrated that individuals who were coprescribed opioid RMG had higher adjusted probability of continued OAT receipt or reengagement compared with those not receiving opioid RMG.

Incremental expenditures attributable to daily dispensation and witnessed ingestion for opioid agonist treatment in British Columbia: 2014-20.

BACKGROUND AND AIM: While daily witnessed opioid agonist treatment (OAT) ingestion is common in British Columbia (BC), Canada, and elsewhere, sparse evidence supports this resource-intensive practice. Many settings across North America relaxed restrictions for take-home dosing during the COVID-19 pandemic and have reported consistent or improved patient outcomes. This study measured excess expenditures attributed to daily witnessed pharmacy dispensing compared with weekly or biweekly dispensation schedules. DESIGN, SETTING AND PARTICIPANTS: This study was a population-level retrospective analysis. We included all methadone, buprenorphine/naloxone and slow-release oral morphine dispensations in BC from 1 January 2014 to 30 December 2020. A total of 24 357 107 OAT dispensations among 51 195 unique individuals with 122 793 person-years of follow-up were included during the study period. MEASUREMENTS: Total expenditures for each person-week of OAT with an estimated expenditure under two scenarios are as follows: (1) a weekly dispensation scenario and (2) a biweekly dispensation scenario. FINDINGS: We estimated excess expenditures attributable to current dispensing practices of between $38 million (2014) and $47.4 million (2018) compared with a hypothetical weekly dispensing schedule, and $43.9 million (2014) to $54.9 million (2018) compared with biweekly dispensing. The majority of these expenditures (58-64%) were attributed to pharmacy dispensing fees ($23 million in 2014 to $30 million in 2018 compared with weekly dispensing; $26.6 million in 2014 to $34.7 million in 2018 compared with biweekly dispensing). CONCLUSION: Daily witnessed opioid agonist treatment ingestion results in more than $30 million in excess expenditures annually in the province of British Columbia, Canada compared with the costs of weekly or biweekly dispensation schedules.