A Literature Review Examining Primary Outcomes of Medication Treatment Studies for Opioid Use Disorder: What Outcome Should Be Used to Measure Opioid Treatment Success?

Empirically contrasting urine drug screening-based opioid use disorder treatment outcome definitions

BACKGROUND AND AIMS

A lack of consensus on the optimal outcome measures to assess opioid use disorder (OUD) treatment efficacy and their precise definition and computation has hampered the pooling of research data for evidence synthesis and meta-analyses. This study aimed to empirically contrast multiple clinical trial definitions of treatment success by applying them to the same dataset.

METHODS

Data analysis used a suite of functions, developed as a software package for the R language, to operationalize 61 treatment outcome definitions based on urine drug screening (UDS) results. Outcome definitions were derived from clinical trials that are among the most influential in the OUD treatment field. Outcome functions were applied to a harmonized dataset from three large-scale National Drug Abuse Treatment Clinical Trials Network (CTN) studies, which tested various medication for OUD (MOUD) options (n = 2492). Hierarchical clustering was employed to empirically contrast outcome definitions.

RESULTS

The optimal number of clusters identified was three. Cluster 1, comprising eight definitions focused on detecting opioid-positive UDS, did not include missing UDS in outcome calculations, potentially resulting in inflated rates of treatment success. Cluster 2, with the highest variability, included 10 definitions characterized by strict criteria for treatment success, relying heavily on UDS results from either a brief period or a single study visit. The 43 definitions in Cluster 3 represented a diverse range of outcomes, conceptualized as measuring abstinence, use reduction and relapse. These definitions potentially offer more balanced measures of treatment success or failure, as they avoid the extreme methodologies characteristic of Clusters 1 and 2.

CONCLUSIONS

Clinical trials using urine drug screening (UDS) for objective substance use assessment in outcome definitions should consider (1) incorporating missing UDS data in outcome computation and (2) avoiding over-reliance on UDS data confined to a short time frame or the occurrence of a single positive urine test following a period of abstinence.

Mediating effect of craving on the impact of buprenorphine/naloxone and methadone treatment on opioid use: Results from a randomized controlled trial

BACKGROUND

The relationship between opioid craving and opioid use is unclear. We sought to determine to what extent craving mediated the relationship between opioid agonist therapy and changes in opioid use.

METHODS

Data came from a pragmatic, 24-week, pan-Canadian, multi-centric, open-label, randomized controlled trial comparing flexible buprenorphine/naloxone take-home doses to standard supervised methadone models of care for the treatment of prescription-type opioid use disorder. Participants were randomly allocated to buprenorphine/naloxone or methadone models of care. 270 people with prescription-type opioid use disorder were included in analyses. There were 93 women (34.4%) and 2 transgender (0.7%) participants. Most participants were white (67.4%), 45.9% reported unstable living conditions, and 44.8% had psychiatric comorbidities. Generalized linear mixed models followed by mediation analysis estimated the direct effect of treatment group on Timeline Followback-reported next-week opioid use and the indirect effect through past 24-hour opioid craving measured using the Brief Substance Craving Scale at week 2, 6, 10, 14, 18 and 22.

RESULTS

Upon mediation analysis, the average direct effect of treatment on opioid use was 0.465 (95 % CI = 0.183 to 0.751, p < 0.001). The average causal mediated effect was 0.144 (95 % CI = 0.021 to 0.110; p < 0.001). Craving accounted for 23.6 % of the effect of treatment on opioid use (p < 0.001).

CONCLUSIONS

Past 24-hour craving was associated with increased next-week opioid use; however, craving only partially mediated the effect of buprenorphine/naloxone and methadone on next-week opioid use. Research is needed to develop a comprehensive understanding of factors mediating opioid use during opioid agonist therapy.

Buprenorphine-naloxone vs. extended-release naltrexone for opioid use disorder in individuals with and without criminal legal involvement: A secondary analysis of the X:BOT randomized controlled trial

INTRODUCTION

There is uncertainty about whether criminal legal involvement (CLI) impacts the effectiveness of medications for opioid use disorder (MOUD). We aimed to determine whether CLI modifies the association between buprenorphine-naloxone (BUP-NX) vs. extended-release naltrexone (XR-NTX) and MOUD treatment outcomes.

METHODS

We conducted a secondary analysis of X:BOT, a 24-week multi-center randomized controlled trial comparing treatment outcomes between BUP-NX (n = 287) and XR-NTX (n = 283) in the general population. We used baseline Additional Severity-Index Lite responses to identify patients with recent CLI (n = 342), defined as active CLI and/or CLI in the past 30 days, and lifetime incarceration (n = 328). We explored recent CLI and lifetime incarceration as potential effect modifiers of BUP-NX vs. XR-NTX effectiveness on relapse, induction, and overdose. We conducted both intention-to-treat and per-protocol analyses for each outcome.

RESULTS

In intention-to-treat analyses, recent CLI modified the effect of BUP-NX vs. XR-NTX on odds of successful induction (p = 0.03) and hazard of overdose (p = 0.04), but it did not modify the effect on hazard of relapse (p = 0.23). All participants experienced lower odds of successful induction with XR-NTX compared to BUP-NX, but the relative likelihood of successful induction with BUP-NX was lower than XR-NTX among individuals with recent CLI (OR: 0.25, 95 % CI: 0.13-0.47, p < 0.001) compared to those without recent CLI (OR: 0.04, 95 % CI: 0.01-0.19, p < 0.001). Participants with recent CLI experienced similar hazard of overdose with XR-NTX and BUP-NX (HR: 1.12, 95 % CI: 0.42-3.01, p = 0.82), whereas those without recent CLI experienced greater hazard of overdose with XR-NTX compared to BUP-NX (HR: 12.60, 95 % CI: 1.62-98.03, p = 0.02). In per-protocol analyses, recent CLI did not modify the effect of MOUD on hazard of overdose (p = 0.10) or relapse (p = 0.41). Lifetime incarceration did not modify any outcome.

CONCLUSIONS

Compared to individuals without recent CLI, individuals with recent CLI experienced decreased relative effectiveness of BUP-NX compared to XR-NTX for induction and overdose outcomes. This highlights the importance of considering the impact of recent CLI on opioid use disorder treatment outcomes. Future research should explore the mechanisms through which recent CLI modifies MOUD effectiveness and aim to improve MOUD effectiveness for individuals with recent CLI.

A Harm Reduction Framework for Integrated Treatment of Co-Occurring Opioid Use Disorder and Trauma-Related Disorders

The opioid epidemic has exposed a gulf in mental health research, treatment, and policy: Most patients with comorbid trauma-related disorder (TRD) and opioid use disorder (OUD) (TRD + OUD) remain undiagnosed or unsuccessfully treated for the combination of TRD symptoms and opioid use. TRD treatments tend to be psychotherapies that are not accessible or practical for many individuals with TRD + OUD, due to TRD treatment models not systematically incorporating principles of harm reduction (HR). HR practices prioritize flexibility and unequivocally improve outcomes and save lives in the treatment of OUD. Considering the urgent need to improve TRD + OUD treatment and outcomes, we propose that the OUD and TRD fields can be meaningfully reconciled by integrating HR principles with classic phasic treatment for TRD. Adding a "prestabilization" phase of treatment for TRD - largely analogous to the precontemplation Stage of Change - creates opportunities to advance research, clinical practice, and policies and potentially improve patient outcomes.

Exploring the performance of during-treatment substance use outcome measures in predicting longer-term psychosocial functioning and post-treatment abstinence

BACKGROUND

The selection of appropriate efficacy endpoints in clinical trials has been a long-standing challenge for the substance use disorder field. Using data from a large, multi-site National Drug Abuse Treatment Clinical Trials Network trial (CTN-0044; n=474), this secondary data analysis aimed to explore whether specific proximal (during-treatment) substance use outcome measures predict longer-term improvements in psychosocial functioning and post-treatment abstinence, and whether predictions vary depending on the specific substance (cannabis, cocaine/stimulants, opioids, and alcohol).

METHODS

Generalized linear mixed models examined associations between six during-treatment substance use outcome measures and social functioning impairment (Social Adjustment Scale Self-Report) and severity of psychiatric symptoms (Brief Symptom Inventory-18) at end-of-treatment, and 3- and 6-months after treatment as well as post-treatment abstinence.

RESULTS

Maximum days of consecutive abstinence, proportion of days abstinent, ≥3 weeks of continuous abstinence, and the proportion of urine specimens negative for the primary substance were associated with post-treatment psychiatric and social functioning improvement and abstinence. However, only the effects of abstinence during the last 4 weeks of the treatment period on all three post-treatment outcomes was stable over time and did not differ between primary substance groups. In contrast, complete abstinence during the 12-week treatment period was not consistently associated with functioning improvements.

CONCLUSIONS

Substance use outcome measures capturing the duration of primary substance abstinence during treatment are suitable predictors of post-treatment abstinence and longer-term psychosocial functioning improvement. Binary outcomes, such as end-of-treatment abstinence, may be particularly stable predictors and attractive given their ease of computation and straightforward clinical interpretability.

Psychosocial challenges affecting patient-defined medication for opioid use disorder treatment outcomes in a low-income, underserved population: Application of the social-ecological framework

INTRODUCTION

Successful engagement with medication treatment for opioid use disorder is an important focus in reducing mortality associated with the opioid crisis. Mortality remains at unacceptably high levels, pointing to a need for improved understanding of factors that affect medication for opioid use disorder outcomes. This study aims to understand how barriers co-occur and interact to interfere with outcomes in methadone treatment for a low-income, underserved patient population with opioid use disorder.

METHODS

This study was conducted at a community-based drug treatment center that serves a predominately low-income, racially diverse population. Guided by the social-ecological framework, we analyzed semi-structured interviews and focus groups with patients and providers working in opioid use disorder care and recovery across Baltimore City (N = 32) to assess factors that influence methadone treatment outcomes, and how barriers co-occur and interact to worsen treatment outcomes. The study used patient-centered definitions to describe successful treatment outcomes.

RESULTS

Barriers described by both patients and providers fit into several broad levels: individual, interpersonal, institutional, community, and stigma. Participants described co-occurrence of many barriers. Further, the study identified potential interactive effects, such that interrelated barriers were seen as fueling one another and having a deleterious effect on treatment outcomes. Specifically, interrelationships between barriers were described for 1) unstable housing with social influences and mental health factors; 2) transportation with poor physical health and other competing responsibilities; 3) treatment program policies and schedule with competing responsibilities; and 4) stigma with poor physical and mental health.

CONCLUSIONS

Understanding barriers to successful medication for opioid use disorder outcomes and considering their co-occurrence may help to identify and promote interventions to mitigate their impact. This work is intended to guide future research to adapt conceptual frameworks for understanding psychosocial and structural barriers affecting opioid use disorder treatment and ultimately intervention efforts to improve treatment outcomes.

Variability in opioid use disorder clinical presentations and treatment in the emergency department: A mixed-methods study

BACKGROUND

There is strong evidence for emergency department (ED)-initiated treatment of opioid use disorder (OUD). However, implementation is variable, and ED management of OUD may differ by clinical presentation. Our aim was to use mixed methods to explore variation in ED-based OUD care by patient clinical presentation and understand barriers and facilitators to ED implementation of OUD treatment across scenarios.

METHODS

We analyzed treatment outcomes in OUD-related visits within three urban, academic EDs from 12/2018 to 7/2020 following the implementation of interventions to increase ED-initiated OUD treatment. We assessed differences in treatment with medications for OUD (MOUDs) by clinical presentation (overdose, withdrawal, others). These data were integrated with results from 5 focus groups conducted with 28 ED physicians and nurses January to April 2020 to provide a richer understanding of clinician perspectives on caring for ED patients with OUD.

RESULTS

Of the 1339 total opioid-related visits, there were 265 (20%) visits for overdose, 123 (9%) for withdrawal, and 951 (71%) for other OUD-related conditions. 23% of patients received MOUDs during their visit or at discharge. Treatment with MOUDs was least common in overdose presentations (6%) and most common in withdrawal presentations (69%, p < 0.001). Buprenorphine was prescribed at discharge in 15% of visits, including 42% of withdrawal visits, 14% of other OUD-related visits, and 5% of overdose visits (p < 0.001). In focus groups, clinicians highlighted variation in ED presentations among patients with OUD. Clinicians also highlighted key aspects necessary for successful treatment initiation including perceived patient receptivity, provider confidence, and patient clinical readiness.

CONCLUSIONS

ED-based treatment of OUD differed by clinical presentation. Clinician focus groups identified several areas where targeted guidance or novel approaches may improve current practices. These results highlight the need for tailored clinical guidance and can inform health system and policy interventions seeking to increase ED-initiated treatment for OUD.

Sorting through life: evaluating patient-important measures of success in a medication for opioid use disorder (MOUD) treatment program

BACKGROUND

Medication for opioid use disorder (MOUD) is the gold standard treatment for opioid use disorder. Traditionally, "success" in MOUD treatment is measured in terms of program retention, adherence to MOUD, and abstinence from opioid and other drug use. While clinically meaningful, these metrics may overlook other aspects of the lives of people with opioid use disorder (OUD) and surprisingly do not reflect the diagnostic criteria for OUD.

METHODS

Authors identified items for a pilesorting task to identify participant-driven measures of MOUD treatment success through semi-structured interviews. Interviews were transcribed verbatim and coded in Nvivo using directed and conventional content analysis to identify measures related to treatment success and quality of life goals. Participants of a low-threshold MOUD program were recruited and asked to rank identified measures in order of importance to their own lives. Multidimensional scaling (MDS) compared the similarity of items while non-metric MDS in R specified a two-dimensional solution. Descriptive statistics of participant demographics were generated in SPSS.

RESULTS

Sixteen semi-structured interviews were conducted between June and August 2020 in Philadelphia, PA, USA, and 23 measures were identified for a pilesorting activity. These were combined with 6 traditional measures for a total list of 29 items. Data from 28 people were included in pilesorting analysis. Participants identified a combination of traditional and stakeholder-defined recovery goals as highly important, however, we identified discrepancies between the most frequent and highest ranked items within the importance categories. Measures of success for participants in MOUD programs were complex, multi-dimensional, and varied by the individual. However, some key domains such as emotional well-being, decreased drug use, and attendance to basic functioning may have universal importance. The following clusters of importance were identified: emotional well-being, decreased drug use, and human functioning.

CONCLUSIONS

Outcomes from this research have practical applications for those working to provide services in MOUD programs. Programs can use aspects of these domains to both provide patient-centered care and to evaluate success. Specifics from the pilesorting results may also inform approaches to collaborative goal setting during treatment.

Clinical Trial Design Challenges and Opportunities for Emerging Treatments for Opioid Use Disorder: A Review

Importance

Novel treatments for opioid use disorder (OUD) are needed to address both the ongoing opioid epidemic and long-standing barriers to existing OUD treatments that target the endogenous μ-opioid receptor (MOR) system. The goal of this review is to highlight unique clinical trial design considerations for the study of emerging treatments for OUD that address targets beyond the MOR system. In November 2019, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the US Food and Drug Administration sponsored a meeting to discuss the current evidence regarding potential treatments for OUD, including cannabinoids, psychedelics, sedative-hypnotics, and immunotherapeutics, such as vaccines.

Observations

Consensus recommendations are presented regarding the most critical elements of trial design for the evaluation of novel OUD treatments, such as: (1) stage of treatment that will be targeted (eg, seeking treatment, early abstinence/detoxification, long-term recovery); (2) role of treatment (adjunctive with or independent of existing OUD treatments); (3) primary outcomes informed by patient preferences that assess opioid use (including changes in patterns of use), treatment retention, and/or global functioning and quality of life; and (4) adverse events, including the potential for opioid-related relapse or overdose, especially if the patient is not simultaneously taking maintenance MOR agonist or antagonist medications.

Conclusions and Relevance

Applying the recommendations provided here as well as considering input from people with lived experience in the design phase will accelerate the development, translation, and uptake of effective and safe therapeutics for individuals struggling with OUD.

Impact of Impulsivity, Hyperactivity, and Inattention on Discontinuation Rate among Opioid-Dependent Patients Treated with Extended-Release Naltrexone

Previous studies have indicated elevated levels of impulsivity, hyperactivity, and inattention (IHI) among opioid-dependent patients seeking outpatient treatment with extended-release naltrexone (XR-NTX). This led us to hypothesize that IHI may be associated with a higher discontinuation rate for XR-NTX treatment. In a group of 162 patients with opioid dependence, discontinuation prior to the full 24 weeks of the study period (six injections and attending the study visit at 24 weeks) occurred in 49% of the patients, primarily in the early stage of treatment. IHI above the clinical cut-off on the adult ADHD self-report scale (ASRS) was not associated with a risk of premature discontinuation. This finding was not altered when controlling for socio-demographics, substance, use and mental health severity. Conclusively, high levels of IHI per se is not contradictive for XR-NTX treatment in regard to concern for premature discontinuation.

Rationale, design and methods of VA-BRAVE: a randomized comparative effectiveness trial of two formulations of buprenorphine for treatment of opioid use disorder in veterans

Background

To address the US opioid epidemic, there is an urgent clinical need to provide persons with opioid use disorder (OUD) with effective medication treatments for OUD (MOUD). Formulations of sublingual buprenorphine/naloxone (SL-BUP/NLX) are considered the standard of care for OUD including within the Veterans Healthcare Administration (VHA). However, poor retention on MOUD undermines its effectiveness. Long-acting injectable monthly buprenorphine (INJ-BUP) (e.g., Sublocade®) has the potential to improve retention and therefore reduce opioid use and overdose. Designing and conducting studies for OUD pose unique challenges. The strategies and solutions to some of these considerations in designing Cooperative Studies Program (CSP) 2014, Buprenorphine for Treating Opioid Use Disorder in Veterans (VA-BRAVE), a randomized, 20-site, clinical effectiveness trial comparing INJ-BUP to SL-BUP/NLX conducted within the VHA may provide valuable guidance for others confronted with similar investigation challenges.

Methods

This 52-week, parallel group, open-label, randomized controlled trial (RCT) evaluates the comparative effectiveness of two current FDA-approved formulations of buprenorphine: (1) daily SL-BUP/NLX vs. (2) monthly (28-day) INJ-BUP for Veterans with moderate to severe OUD (n = 952). The primary outcomes are (1) retention in MOUD and (2) opioid abstinence. Secondary outcomes include measures of other drug use, psychiatric symptoms, medical outcomes including prevalence rates of HIV, hepatitis B and C as well as social outcomes (housing instability, criminal justice involvement), service utilization and cost-effectiveness. Special considerations in conducting a comparative effectiveness trial with this population and during COVID-19 pandemic were also included.

Discussion

The evaluation of the extended-release formulation of buprenorphine compared to the standard sublingual formulation in real-world VHA settings is of paramount importance in addressing the opioid epidemic. The extent to which this new treatment facilitates retention, decreases opioid use, and prevents severe sequelae of OUD has not been studied in any long-term trial to date. Positive findings in this trial could lead to widespread adoption of MOUD, and, if proven superior INJ-BUP, by clinicians throughout the VHA and beyond. This treatment has the potential to reduce opioid use among Veterans, improve medical, psychological, and social outcomes, and save lives at justifiable cost.

Trial registration Registered at Clinicaltrials.gov NCT04375033

Interim opioid agonist treatment for opioid addiction: a systematic review

Background

Opioid use disorder is a public health problem and treatment variability, coverage and accessibility poses some challenges. The study’s objective is to review the impact of interim opioid agonist treatment (OAT), a short-term approach for patients awaiting standard OAT, in terms of treatment retention, access to standard OAT, quality of life and satisfaction with treatment.

Method

We conducted a systematic review searching MEDLINE, EMBASE, PsycINFO, and CENTRAL up to May 2020. Due to variability between studies and outcome measurements, we did not pool effect estimates and reported a narrative synthesis of findings rating their certainty according to GRADE.

Results

We identified 266 unique records and included five randomized trials with some limitations in risk of bias and one observational study limited by selection bias. The studies assessed similar approaches to interim OAT but were compared to three different control conditions. Four studies reported on treatment retention at 4 months or less with no significant differences between interim OAT and waiting list or standard OAT. Two studies reported treatment retention at 12 months with no differences between interim OAT and standard OAT. Two trials assessed access to standard OAT and showed significant differences between interim OAT and waiting list for standard OAT. We rated the quality of evidence for these outcomes as moderate due to the impact of risk of bias. Data on quality of life or satisfaction with treatment was suboptimal.

Conclusions

Interim OAT is likely more effective than a waiting list for standard OAT in access to treatment, and it is probably as effective as standard OAT regarding treatment retention.

PROSPERO registration CRD42018116269.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-022-00592-x.

What Will It Take to End HIV in the United States? : A Comprehensive, Local-Level Modeling Study

BACKGROUND

The Ending the HIV Epidemic (EHE) initiative aims to reduce incident HIV infections by 90% over a span of 10 years. The intensity of interventions needed to achieve this for local epidemics is unclear.

OBJECTIVE

To estimate the effect of HIV interventions at the city level.

DESIGN

A compartmental model of city-level HIV transmission stratified by age, race, sex, and HIV risk factor was developed and calibrated.

SETTING

32 priority metropolitan statistical areas (MSAs).

PATIENTS

Simulated populations in each MSA.

INTERVENTION

Combinations of HIV testing and preexposure prophylaxis (PrEP) coverage among those at risk for HIV, plus viral suppression in persons with diagnosed HIV infection.

MEASUREMENTS

The primary outcome was the projected reduction in incident cases from 2020 to 2030.

RESULTS

Absent intervention, HIV incidence was projected to decrease by 19% across all 32 MSAs. Modest increases in testing (1.25-fold per year), PrEP coverage (5 percentage points), and viral suppression (10 percentage points) across the population could achieve reductions of 34% to 67% by 2030. Twenty-five percent PrEP coverage, testing twice a year on average, and 90% viral suppression among young Black and Hispanic men who have sex with men (MSM) achieved similar reductions (13% to 68%). Including all MSM and persons who inject drugs could reduce incidence by 48% to 90%. Thirteen of 32 MSAs could achieve greater than 90% reductions in HIV incidence with large-scale interventions that include heterosexuals. A web application with location-specific results is publicly available (www.jheem.org).

LIMITATION

The COVID-19 pandemic was not represented.

CONCLUSION

Large reductions in HIV incidence are achievable with substantial investment, but the EHE goals will be difficult to achieve in most locations. An interactive model that can help policymakers maximize the effect in their local environments is presented.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Long-acting buprenorphine vs. naltrexone opioid treatments in CJS-involved adults (EXIT-CJS)

The EXIT-CJS (N = 1005) multisite open-label randomized controlled trial will compare retention and effectiveness of extended-release buprenorphine (XR-B) vs. extended-release naltrexone (XR-NTX) to treat opioid use disorder (OUD) among criminal justice system (CJS)-involved adults in six U.S. locales (New Jersey, New York City, Delaware, Oregon, Connecticut, and New Hampshire). With a pragmatic, noninferiority design, this study hypothesizes that XR-B (n = 335) will be noninferior to XR-NTX (n = 335) in retention-in-study-medication treatment (the primary outcome), self-reported opioid use, opioid-positive urine samples, opioid overdose events, and CJS recidivism. In addition, persons with OUD not eligible or interested in the RCT will be recruited into an enhanced treatment as usual arm (n = 335) to examine usual care outcomes in a quasi-experimental observational cohort.