Assessing the determinants of completing OAT induction and long-term retention: A population-based study in British Columbia, Canada

Opioid agonist treatment outcomes among individuals with a history of nonfatal overdose: Findings from a pragmatic, pan-Canadian, randomized control trial

BACKGROUND AND OBJECTIVES

History of nonfatal overdose (NFO) is common among people who use opioids, but little is known about opioid agonist treatment (OAT) outcomes for this high-risk subpopulation. The objective of this study was to investigate the relative effectiveness of buprenorphine/naloxone and methadone on retention and suppression of opioid use among individuals with opioid use disorder (OUD) and history of NFO.

METHODS

Secondary analysis of a pan-Canadian pragmatic trial comparing flexible take-home buprenorphine/naloxone and supervised methadone for people with OUD and history of NFO. Logistic regression was used to examine the impact of OAT on retention in the assigned or in any OAT at 24 weeks and analysis of covariance was used to examine the mean difference in opioid use between treatment arms.

RESULTS

Of the 272 randomized participants, 155 (57%) reported at least one NFO at baseline. Retention rates in the assigned treatment were 17.7% in the buprenorphine/naloxone group and 18.4% in the methadone group (adjusted odds ratio [AOR] = 0.54, 95% CI: 0.17-1.54). Rates of retention in any OAT were 28% and 20% in the buprenorphine/naloxone and methadone arms, respectively (AOR = 1.55, 95% CI: 0.65-3.78). There was an 11.9% adjusted mean difference in opioid-free urine drug tests, favoring the buprenorphine/naloxone arm (95% CI: 3.5-20.3; p = .0057).

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Among adults with OUD and a history of overdose, overall retention rates were low but improved when retention in any treatment was considered. These findings highlight the importance of flexibility and patient-centered care to improve retention and other treatment outcomes in this population.

Client preferences for the design and delivery of injectable opioid agonist treatment services: Results from a best-worst scaling task

BACKGROUND AND AIMS

Clinical trials support injectable opioid agonist treatment (iOAT) for individuals with opioid use disorder (OUD) for whom other pharmacological management approaches are not well-suited. However, despite substantial research indicating that person-centered care improves engagement, retention and health outcomes for individuals with OUD, structural requirements (e.g. drug policies) often dictate how iOAT must be delivered, regardless of client preferences. This study aimed to quantify clients' iOAT delivery preferences to improve client engagement and retention.

DESIGN

Cross-sectional preference elicitation survey.

SETTING

Metro Vancouver, British Columbia, Canada.

PARTICIPANTS

124 current and former iOAT clients.

MEASUREMENTS

Participants completed a demographic questionnaire package and an interviewer-led preference elicitation survey (case 2 best-worst scaling task). Latent class analysis was used to identify distinct preference groups and explore demographic differences between preference groups.

FINDINGS

Most participants (n = 100; 81%) were current iOAT clients. Latent class analysis identified two distinct groups of client preferences: (1) autonomous decision-makers (n = 73; 59%) and (2) shared decision-makers (n = 51; 41%). These groups had different preferences for how medication type and dosage were selected. Both groups prioritized access to take-home medication (i.e. carries), the ability to set their own schedule, receiving iOAT in a space they like and having other services available at iOAT clinics. Compared with shared decision-makers, fewer autonomous decision-makers identified as a cis-male/man and reported flexible preferences.

CONCLUSIONS

Injectable opioid agonist treatment (iOAT) clients surveyed in Vancouver, Canada, appear to prefer greater autonomy than they currently have in choosing OAT medication type, dosage and treatment schedule.

What is the ideal time to begin tapering opioid agonist treatment? A protocol for a retrospective population-based comparative effectiveness study in British Columbia, Canada

INTRODUCTION

Opioid agonist treatment (OAT) tapering involves a gradual reduction in daily medication dose to ultimately reach a state of opioid abstinence. Due to the high risk of relapse and overdose after tapering, this practice is not recommended by clinical guidelines, however, clients may still request to taper off medication. The ideal time to initiate an OAT taper is not known. However, ethically, taper plans should acknowledge clients' preferences and autonomy but apply principles of shared informed decision-making regarding safety and efficacy. Linked population-level data capturing real-world tapering practices provide a valuable opportunity to improve existing evidence on when to contemplate starting an OAT taper. Our objective is to determine the comparative effectiveness of alternative times from OAT initiation at which a taper can be initiated, with a primary outcome of taper completion, as observed in clinical practice in British Columbia (BC), Canada.

METHODS AND ANALYSIS

We propose a population-level retrospective observational study with a linkage of eight provincial health administrative databases in BC, Canada (01 January 2010 to 17 March 2020). Our primary outcomes include taper completion and all-cause mortality during treatment. We propose a 'per-protocol' target trial to compare different durations to taper initiation on the likelihood of taper completion. A range of sensitivity analyses will be used to assess the heterogeneity and robustness of the results including assessment of effectiveness and safety.

ETHICS AND DISSEMINATION

The protocol, cohort creation and analysis plan have been classified and approved as a quality improvement initiative by Providence Health Care Research Ethics Board and the Simon Fraser University Office of Research Ethics. Results will be disseminated to local advocacy groups and decision-makers, national and international clinical guideline developers, presented at international conferences and published in peer-reviewed journals electronically and in print.

Patient and Provider Perspectives on Processes of Engagement in Outpatient Treatment for Opioid Use Disorder: A Scoping Review

Effective treatment for opioid use disorder (OUD) is available, but patient engagement is central to achieving care outcomes. We conducted a scoping review to describe patient and provider-reported strategies that may contribute to patient engagement in outpatient OUD care delivery. We searched PubMed and Scopus for articles reporting patient and/or provider experiences with outpatient OUD care delivery. Analysis included: (1) describing specific engagement strategies, (2) mapping strategies to patient-centered care domains, and (3) identifying themes that characterize the relationship between engagement and patient-centered care. Of 3,222 articles screened, 30 articles met inclusion criteria. Analysis identified 14 actionable strategies that facilitate patient engagement and map to all patient-centered care domains. Seven themes emerged that characterize interpersonal approaches to OUD care engagement. Interpersonal interactions between patients and providers play a pivotal role in encouraging engagement throughout OUD treatment. Future research is needed to further evaluate promising engagement strategies.

Associations with experience of non-fatal opioid overdose in British Columbia, Canada: a repeated cross sectional survey study

INTRODUCTION

Lives lost in North America due to the unregulated drug poisoning emergency are preventable and those who survive an opioid overdose may suffer long-term disability. Rates of opioid overdose more than doubled following the onset of the COVID-19 pandemic in British Columbia, Canada.

MATERIALS AND METHODS

Our analytical sample was comprised of 1447 participants from the 2018, 2019, and 2021 Harm Reduction Client Survey who responded yes or no to having experienced an opioid overdose in the past 6 months. Participants were recruited from harm reduction sites from across British Columbia. We used logistic regression to explore associations of experiencing an opioid overdose.

RESULTS

Overall, 21.8% of participants reported experiencing an opioid overdose in the last six months (18.2% in 2019 and 26.6% in 2021). The following factors were positively associated with increased adjusted odds of experiencing a non-fatal opioid overdose: cis men relative to cis women (AOR 1.49, 95% CI 1.10-2.02), unstably housed compared to people with stable housing (AOR 1.87, 95% CI 1.40-2.50), and participants from 2021 compared to those from 2019 (AOR 3.06, 95% CI 1.57-5.97). The effects of both previous experience of a stimulant overdose and having witnessed an opioid overdose depended on the year of study, with both effects decreasing over subsequent years.

CONCLUSIONS

Overdoses have increased over time; in 2021 more than one in four participants experienced an overdose. There is an urgent need for policy and program development to meaningfully address the unregulated drug poisoning emergency through acceptable life-saving interventions and services to prevent overdoses and support overdose survivors.

Safety and Efficacy of Rapid Methadone Titration for Opioid Use Disorder in an Inpatient Setting: A Retrospective Cohort Study

OBJECTIVES

Inpatient guidelines for methadone titration do not exist, whereas outpatient guidelines lack flexibility and do not consider individual opioid tolerance. The evaluation of rapid, adaptable titration protocols may allow more patient-centered and effective treatment for opioid use disorder in the fentanyl era.

METHODS

This study performed a retrospective chart review of patients 18 years or older with opioid use disorder who were initiated on methadone at a single academic urban hospital using a rapid divided dose protocol between November 2019 and November 2020. The primary outcome was adverse events associated with methadone, specifically opioid toxicity or sedation requiring increased medical observation or intervention. The secondary outcome was total daily dose of methadone received on day 7 of titration.

RESULTS

Ninety-eight patients were included for a total of 168 visits. Sixty-five (66%) were male, with a median age of 38 years (interquartile range, 31-42 years). Sedation occurred in 2 patients (1%), who required either naloxone administration or transfer to an intensive care unit for monitoring. Of the 135 visits where patients received at least 7 days of methadone, the mean dose on day 1 was 41 mg (SD, 9.6 mg) and on day 7 was 65 mg (SD, 20.9 mg).

CONCLUSIONS

In this inpatient cohort, rapid methadone titration was well tolerated and resulted in patients reaching higher doses of methadone than would be possible with a standard schedule, with few adverse events. Given the known effective dose range, this approach may result in shorter time to clinical stabilization and suggests that alternative methadone titration schedules may be safe and effective in appropriately selected patients.

Peer-led safer supply and opioid agonist treatment medication distribution: a case study from rural British Columbia

BACKGROUND

British Columbia (BC) has been facing a public health emergency of overdose since 2016, with rural regions of the province facing the highest rates of death. Peers (in this case, people with lived experience of substance use) are known to be effective patient navigators in health systems and can play a role in connecting patients to care and reducing overdose risk.

CASE PRESENTATION

We outline a peer-led program focused on opioid agonist treatment and prescribed safe supply medication delivery that began in March 2020 at a clinic in rural BC. The peer takes an Indigenous harm reduction approach and is focused on meeting the needs of the whole person. The peer has regular contact with approximately 50 clients and navigates medication delivery and appointments for approximately 10-15 people each day. Clients have been retained on the medication, and experienced improvement in other outcomes, including securing housing, employment and managing acute and chronic health conditions. The peer has established contact with clients since March 2020 to support engagement with health care and continuity of medication access. This program highlights the importance and value of peer-led work and need for further investments in peer-led programs to respond to the unregulated drug poisoning crisis.

CONCLUSIONS

This peer-led intervention is a promising approach to engaging people who remain disconnected from health services in care in a rural community. This model could be adapted to other settings to support patient contact with the health system and medication access and continuity, with the ultimate goal of reducing overdose risk.

Characterizing opioid agonist therapy uptake and factors associated with treatment retention among people with HIV in British Columbia, Canada

Accidental overdoses are now the leading cause of death among people with HIV (PWH) in British Columbia (BC). We examined the utilization and retention of opioid agonist therapy (OAT). Adult PWH (≥19 years) with ≥ 1 OAT dispensation in BC between 2008 and 2020 were included (n = 1,515). OAT treatment episodes were formed based on specific criteria for slow-release oral morphine (SROM), methadone, injectable OAT (iOAT), and buprenorphine/naloxone. Retention in treatment was defined as any episode lasting ≥ 12 months. Logistic regression with generalized estimating equations modeled retention-associated factors. There was a 56.6% decline in OAT retention over time. Buprenorphine treatment exhibited significantly lower odds of retention (OR: 0.58; 95% CI: 0.36-0.92) compared to methadone. Conversely, no significant change in retention odds was observed for SROM (0.72; 0.33-1.54) and iOAT (0.81; 0.31-2.12). Factors associated with increased odds of retention included a 10-year increase in age (1.69; 1.46-1.95), previous retention history (1.96; 1.40-2.73), achieving OAT therapeutic dose (8.22; 6.67-10.14), and suppressed HIV viral load (1.35; 1.10-1.67). Individuals with a lifetime HCV diagnosis receiving iOAT were more likely to retain (3.61; 1.20-10.83). Each additional year on OAT during the study period was associated with a 4% increase in the odds of retention. A significant proportion of PWH had a history of OAT prescribing but experienced low retention rates. Retention outcomes were more positive for SROM and iOAT. The association between OAT medication type and retention odds may be particularly influenced by HCV diagnosis. Optimal management of opioid use disorder among PWH, with an emphasis on attaining the therapeutic dose is crucial.

The impact of methamphetamine use on medications for opioid use disorder (MOUD) treatment retention: a scoping review

BACKGROUND

An emerging public health threat of methamphetamine/opioid co-use is occurring in North America, including increases in overdoses related to concomitant methamphetamine/opioid use. This presents a potential risk to established treatments for opioid use disorder (i.e., medications for opioid use disorder [MOUD]). To date, few studies have examined the impact of methamphetamine use on MOUD-related outcomes, and no studies have synthesized data on MOUD retention.

METHODS

A scoping review was undertaken to examine the impact of methamphetamine use on MOUD retention. All original published research articles were searched in Embase, MEDLINE, PsychINFO, CINAHL, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Cochrane Protocols, and Google scholar databases. Data were extracted into a standardized data extraction chart. Findings were presented narratively.

RESULTS

All eight included studies demonstrated an increased likelihood of treatment discontinuation or dropout among patients enrolled in MOUD who used methamphetamine. The frequency of methamphetamine use was also associated with MOUD dropout, in that those who used methamphetamine more often were more likely to discontinue MOUD. The definitions and measurements of MOUD retention varied considerably, as did the magnitude of effect size.

CONCLUSIONS

Results indicate that methamphetamine use has an undesirable impact on MOUD retention and results in an increased risk of treatment discontinuation or dropout. Strategies to identify concurrent methamphetamine use among individuals engaging in MOUD and educate them on the increased risk for dropout should be undertaken. Further research is needed to understand how MOUD retention among patients with concomitant opioid and methamphetamine use can be improved.

Buprenorphine versus methadone for the treatment of opioid dependence: a systematic review and meta-analysis of randomised and observational studies

BACKGROUND

Opioid dependence is associated with substantial health and social burdens, and opioid agonist treatment (OAT) is highly effective in improving multiple outcomes for people who receive this treatment. Methadone and buprenorphine are common medications provided as OAT. We aimed to examine buprenorphine compared with methadone in the treatment of opioid dependence across a wide range of primary and secondary outcomes.

METHODS

We did a systematic review and meta-analysis in accordance with GATHER and PRISMA guidelines. We searched Embase, MEDLINE, CENTRAL, and PsycINFO from database inception to Aug 1, 2022; clinical trial registries and previous relevant Cochrane reviews were also reviewed. We included all RCTs and observational studies of adults (aged ≥18 years) with opioid dependence comparing treatment with buprenorphine or methadone. Primary outcomes were retention in treatment at 1, 3, 6, 12, and 24 months, treatment adherence (measured through doses taken as prescribed, dosing visits attended, and biological measures), or extra-medical opioid use (measured by urinalysis and self-report). Secondary outcomes were use of benzodiazepines, cannabis, cocaine, amphetamines, and alcohol; withdrawal; craving; criminal activity and engagement with the criminal justice system; overdose; mental and physical health; sleep; pain; global functioning; suicidality and self-harm; and adverse events. Single-arm cohort studies and RCTs that collected data on buprenorphine retention alone were also reviewed. Data on study, participant, and treatment characteristics were extracted. Study authors were contacted to obtain additional data when required. Comparative estimates were pooled with use of random-effects meta-analyses. The proportion of individuals retained in treatment across multiple timepoints was pooled for each drug. This study is registered with PROSPERO (CRD42020205109).

FINDINGS

We identified 32 eligible RCTs (N=5808 participants) and 69 observational studies (N=323 340) comparing buprenorphine and methadone, in addition to 51 RCTs (N=11 644) and 124 observational studies (N=700 035) that reported on treatment retention with buprenorphine. Overall, 61 studies were done in western Europe, 162 in North America, 14 in north Africa and the Middle East, 20 in Australasia, five in southeast Asia, seven in south Asia, two in eastern Europe, three in central Europe, one in east Asia, and one in central Asia. 1 040 827 participants were included in these primary studies; however, gender was only reported for 572 111 participants, of whom 377 991 (66·1%) were male and 194 120 (33·9%) were female. Mean age was 37·1 years (SD 6·0). At timepoints beyond 1 month, retention was better for methadone than for buprenorphine: for example, at 6 months, the pooled effect favoured methadone in RCTs (risk ratio 0·76 [95% CI 0·67-0·85]; I·=74·2%; 16 studies, N=3151) and in observational studies (0·77 [0·68-0·86]; I·=98·5%; 21 studies, N=155 111). Retention was generally higher in RCTs than observational studies. There was no evidence suggesting that adherence to treatment differed with buprenorphine compared with methadone. There was some evidence that extra-medical opioid use was lower in those receiving buprenorphine in RCTs that measured this outcome by urinalysis and reported proportion of positive urine samples (over various time frames; standardised mean difference -0·20 [-0·29 to -0·11]; I·=0·0%; three studies, N=841), but no differences were found when using other measures. Some statistically significant differences were found between buprenorphine and methadone among secondary outcomes. There was evidence of reduced cocaine use, cravings, anxiety, and cardiac dysfunction, as well as increased treatment satisfaction among people receiving buprenorphine compared with methadone; and evidence of reduced hospitalisation and alcohol use in people receiving methadone. These differences in secondary outcomes were based on small numbers of studies (maximum five), and were often not consistent across study types or different measures of the same constructs (eg, cocaine use).

INTERPRETATION

Evidence from trials and observational studies suggest that treatment retention is better for methadone than for sublingual buprenorphine. Comparative evidence on other outcomes examined showed few statistically significant differences and was generally based on small numbers of studies. These findings highlight the imperative for interventions to improve retention, consideration of client-centred factors (such as client preference) when selecting between methadone and buprenorphine, and harmonisation of data collection and reporting to strengthen future syntheses.

FUNDING

Australian National Health and Medical Research Council.

Comparative effectiveness of urine drug screening strategies alongside opioid agonist treatment in British Columbia, Canada: a population-based observational study protocol

INTRODUCTION

Urine drug tests (UDTs) are commonly used for monitoring opioid agonist treatment (OAT) responses, supporting the clinical decision for take-home doses and monitoring potential diversion. However, there is limited evidence supporting the utility of mandatory UDTs-particularly the impact of UDT frequency on OAT retention. Real-world evidence can inform patient-centred approaches to OAT and improve current strategies to address the ongoing opioid public health emergency. Our objective is to determine the safety and comparative effectiveness of alternative UDT monitoring strategies as observed in clinical practice among OAT clients in British Columbia, Canada from 2010 to 2020.

METHODS AND ANALYSIS

We propose a population-level retrospective cohort study of all individuals 18 years of age or older who initiated OAT from 1 January 2010 to 17 March 2020. The study will draw on eight linked health administrative databases from British Columbia. Our primary outcomes include OAT discontinuation and all-cause mortality. To determine the effectiveness of the intervention, we will emulate a 'per-protocol' target trial using a clone censoring approach to compare fixed and dynamic UDT monitoring strategies. A range of sensitivity analyses will be executed to determine the robustness of our results.

ETHICS AND DISSEMINATION

The protocol, cohort creation and analysis plan have been classified and approved as a quality improvement initiative by Providence Health Care Research Ethics Board and the Simon Fraser University Office of Research Ethics. Results will be disseminated to local advocacy groups and decision-makers, national and international clinical guideline developers, presented at international conferences and published in peer-reviewed journals electronically and in print.

Smoking identified as preferred mode of opioid safe supply use; investigating correlates of smoking preference through a 2021 cross-sectional study in British Columbia

BACKGROUND

The increasing number of illicit drug toxicity deaths in British Columbia (BC) has led to calls for a regulated (pharmaceutical grade) supply of substances ("safe supply"). In order to inform safe supply recommendations, we aimed to identify why people currently smoke opioids and assess the preferred mode of consumption if people who use opioids were provided with opioid safe supply.

METHODS

The BC Harm Reduction Client Survey (HRCS) is an annual survey that gathers information about people who use drugs' (PWUD) substance use characteristic with the goal of contributing to evidence-based policy. This study utilized data from the 2021 HRCS. The outcome variable was "prefer smoking opioid safe supply" ('yes/no'). Explanatory variables included participants' demographics, drug use, and overdose characteristics. Bivariate and hierarchical multivariable logistic regressions were conducted to identify factors associated with the outcome.

RESULTS

Of 282 total participants who indicated a preference for a mode of consumption for opioid safe supply, 62.4% preferred a smokable option and 19.9% preferred to inject if provided with opioid safe supply. Variables significantly associated with the outcome (preferred smoking) included: being 19-29 years old (AOR=5.95, CI =1.93 - 18.31) compared to >50 years old, having witnessed an overdose in the last 6 months (AOR=2.26, CI=1.20 - 4.28), having smoked opioids in the last 3 days (AOR=6.35, CI=2.98 - 13.53) and having a preference to smoke stimulants safe supply (AOR=5.04, CI=2.53 - 10.07).

CONCLUSION

We found that over half of participants prefer smokable options when accessing opioid safe supply. Currently in BC, there are limited smokable opioid safe supply options as alternatives to the toxic street supply. To reduce overdose deaths, safe supply options should be expanded to accommodate PWUD that prefer smoking opioids.

Cost-effectiveness of flexible take-home buprenorphine-naloxone versus methadone for treatment of prescription-type opioid use disorder

BACKGROUND

Our objective was to examine the cost-effectiveness of flexible take-home buprenorphine-naloxone (BNX) versus methadone alongside the OPTIMA trial in Canada.

METHODS

The OPTIMA study was a pragmatic, open-label, noninferiority, two-arm randomized controlled trial, to assess the comparative effectiveness of flexible take-home BNX vs. methadone in routine clinical care for individuals with prescription-type opioid use disorder. We evaluated cost-effectiveness using a semi-Markov cohort model. Probabilities of overdose were calibrated, accounting for fentanyl prevalence and other overdose risk factors such as naloxone availability. We considered health sector and societal cost perspectives, including costs (2020 CAD) for treatment, health resource use, criminal activity, and health state-specific preference weights as outcomes to calculate incremental cost-effectiveness ratios. Six-month and lifetime (3% annual discount rate) time-horizons were explored.

RESULTS

Over a lifetime time horizon, individuals accumulated -0.144 [CI: -0.302, -0.025] incremental quality-adjusted life years (QALYs) in BNX compared with methadone. Incremental costs were -$2047 [CI: -$39,197, $24,250] from a societal perspective, and -$4549 [CI: -$6332, -$3001] from a health sector perspective. Over a six-month time-horizon, individuals accumulated 0.002 [credible interval (CI): -0.011, 0.016] incremental QALYs in BNX compared with methadone. Incremental costs were -$307 [CI: -$10,385, $8466] from a societal perspective and -$1111 [CI: -$1517, -$631] from a health sector perspective. BNX was dominated (costlier, less effective) in 49.7% of simulations when adopting a societal perspective over a lifetime time horizon.

CONCLUSIONS

Flexible take-home BNX was not cost-effective versus methadone over a lifetime time horizon, resulting from better treatment retention in methadone compared to BNX.

The effects of childhood trauma and mental disorders on treatment engagement, contact with the criminal justice system, and mortality among people with opioid dependence

BACKGROUND

Childhood trauma and mental disorders increase the risk of opioid dependence. We aimed to examine whether childhood trauma and mental disorders are associated with opioid agonist treatment (OAT) engagement, contact with the criminal justice system, and mortality among people with opioid dependence.

METHODS

This observational study linked survey data from 1482 people receiving OAT in Sydney, Australia (2004-2008) to administrative data on OAT, crime, and mortality through 2017. We used survey data to assess childhood trauma, depression, panic disorder, post-traumatic stress disorder (PTSD), borderline personality disorder, anti-social personality disorder (ASPD), and comorbid substance dependence. We used discrete-time analysis to examine time from opioid dependence onset to OAT entry and mortality. Poisson regressions were used to analyze time receiving OAT and number of charges.

RESULTS

Participants with extensive childhood trauma histories and ASPD were less likely to enter OAT and those with depression were more likely to enter OAT in any given year after opioid dependence onset. Panic disorder, PTSD, and borderline personality disorder were associated with less time in OAT. Extensive histories of childhood trauma, PTSD, ASPD, and comorbid substance dependence increased risk of charges for any offence. There were no significant associations between the exposure variables and mortality.

CONCLUSIONS

Our findings suggest that childhood trauma and mental disorders increase the risk of adverse treatment and social outcomes among people with opioid dependence. Interventions that aim to reduce harm among people with opioid dependence may consider the effect of childhood trauma and mental disorders on OAT engagement and crime.