Modeling the evolution of the US opioid crisis for national policy development.

The opioid crisis is a major public health challenge in the United States, killing about 70,000 people in 2020 alone. Long delays and feedbacks between policy actions and their effects on drug-use behavior create dynamic complexity, complicating policy decision-making. In 2017, the National Academies of Sciences, Engineering, and Medicine called for a quantitative systems model to help understand and address this complexity and guide policy decisions. Here, we present SOURCE (Simulation of Opioid Use, Response, Consequences, and Effects), a dynamic simulation model developed in response to that charge. SOURCE tracks the US population aged ≥12 y through the stages of prescription and illicit opioid (e.g., heroin, illicit fentanyl) misuse and use disorder, addiction treatment, remission, and overdose death. Using data spanning from 1999 to 2020, we highlight how risks of drug use initiation and overdose have evolved in response to essential endogenous feedback mechanisms, including: 1) social influence on drug use initiation and escalation among people who use opioids; 2) risk perception and response based on overdose mortality, influencing potential new initiates; and 3) capacity limits on treatment engagement; as well as other drivers, such as 4) supply-side changes in prescription opioid and heroin availability; and 5) the competing influences of illicit fentanyl and overdose death prevention efforts. Our estimates yield a more nuanced understanding of the historical trajectory of the crisis, providing a basis for projecting future scenarios and informing policy planning.

State-level racial and ethnic disparities in buprenorphine treatment duration in the United States.

BACKGROUND AND OBJECTIVES: National trends reveal a concerning escalation in racial and ethnic disparities in buprenorphine treatment duration for opioid use disorder. However, the extent of such disparities at the state level remains largely unexplored. This study aims to examine such disparities at the state level. METHODS: We analyzed 9,040,620 buprenorphine prescriptions dispensed between January 2011 and December 2020 from IQVIA Longitudinal Prescription data. The primary outcome was the difference in median treatment duration between White people and racial and ethnic minorities. We also included a second outcome measurement to quantify the difference in median treatment duration among episodes lasting ≥180 days. Using quantile regressions, we examined racial and ethnic disparities in treatment duration, adjusting for the patient's age, sex, payment type, and calendar year of the treatment episode. All analyses were conducted at the state level. RESULTS: Our study revealed substantial statewide variations in racial and ethnic disparities. Specifically, 21 states showed longer treatment durations for White people across all episodes, and eight states displayed similar trends among episodes lasting ≥180 days. Five states exhibited longer treatment durations for White people in both overall and long-term episodes. Fifteen states showed no racial and ethnic disparities. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: These results are among the first to indicate substantial statewide variations in racial and ethnic disparities in buprenorphine treatment episode duration, providing a critical foundation for targeted interventions to enhance buprenorphine treatment, especially in states confronting such pronounced racial and ethnic disparities.

Economic Evaluation in Opioid Modeling: Systematic Review.

OBJECTIVES: The rapid increase in opioid overdose and opioid use disorder (OUD) over the past 20 years is a complex problem associated with significant economic costs for healthcare systems and society. Simulation models have been developed to capture and identify ways to manage this complexity and to evaluate the potential costs of different strategies to reduce overdoses and OUD. A review of simulation-based economic evaluations is warranted to fully characterize this set of literature. METHODS: A systematic review of simulation-based economic evaluation (SBEE) studies in opioid research was initiated by searches in PubMed, EMBASE, and EbscoHOST. Extraction of a predefined set of items and a quality assessment were performed for each study. RESULTS: The screening process resulted in 23 SBEE studies ranging by year of publication from 1999 to 2019. Methodological quality of the cost analyses was moderately high. The most frequently evaluated strategies were methadone and buprenorphine maintenance treatments; the only harm reduction strategy explored was naloxone distribution. These strategies were consistently found to be cost-effective, especially naloxone distribution and methadone maintenance. Prevention strategies were limited to abuse-deterrent opioid formulations. Less than half (39%) of analyses adopted a societal perspective in their estimation of costs and effects from an opioid-related intervention. Prevention strategies and studies' accounting for patient and physician preference, changing costs, or result stratification were largely ignored in these SBEEs. CONCLUSION: The review shows consistently favorable cost analysis findings for naloxone distribution strategies and opioid agonist treatments and identifies major gaps for future research.

Some law enforcement officers' negative attitudes toward overdose victims are exacerbated following overdose education training.

BACKGROUND: The devastating impact of the current opioid overdose crisis has led to new involvement of law enforcement officers. Training programs have focused on overdose recognition and response without targeting core attitudinal change by covering addiction or harm reduction principles. OBJECTIVES: This study examined the impact of a comprehensive overdose education and naloxone distribution (OEND) training on officers' attitudes toward overdose victims, knowledge of and competence to respond to an opioid overdose, and concerns about using naloxone. The training included the common information about overdose recognition and response, with added components covering broader content about addiction and harm reduction principles and philosophies. METHODS: A total of 787 (83% male) officers were administered surveys before and after attending a 2.5-3 hour comprehensive OEND training. Survey items measured overdose-related knowledge and attitudes, including attitudes about people who use drugs and who overdose. RESULTS: Following the training, participants' overdose-related knowledge and perceived competence to use naloxone improved. However, there were more nuanced changes in attitudes toward overdose victims: though 55.3% of officers reported more positive post-training attitudes, 31% reported more negative attitudes, and 13.7% reported no attitudinal change. Younger officers were most likely to report worsened attitudes. Improvements in attitudes toward overdose victims were associated with reductions in both naloxone-related concerns and risk compensation beliefs. CONCLUSIONS: Despite a comprehensive OEND training that addressed addiction and harm reduction and directly targeted hypothesized drivers of negative attitudes (e.g., risk compensation beliefs), some officers' attitudes worsened after the training. Randomized experiments of different training approaches would elucidate the mediators and moderators underlying these unexpected responses.

Exploring Quality of Primary Care for Patients Who Experience Homelessness and the Clinicians Who Serve Them: What Are Their Aspirations?

To develop and evaluate an effective model of patient-centered, high-quality, homeless-focused primary care, our team explored key domains of primary care that may be important to patients. We anchored our conceptual framework in two reports from the Institute of Medicine (IOM) that defined components of primary care and quality of care. Using questions developed from this framework, we conducted semistructured interviews with 36 homeless-experienced individuals with past-year primary care engagement and 24 health care professionals (clinicians and researchers) who serve homeless-experienced patients in the primary care setting. Template analysis revealed factors important to this population. These included stigma, respect, and perspectives on patient control of medical decision-making in regard to both pain and addiction. For patients experiencing homelessness, the results suggest that quality primary care may have different meanings for patients and professionals, and that services should be tailored to meet homeless-specific needs.

The case for a medication first approach to the treatment of opioid use disorder.

Background: The opioid addiction and overdose crisis continues to ravage communities across the U.S. Maintenance pharmacotherapy using buprenorphine or methadone is the most effective intervention for Opioid Use Disorder (OUD), yet few have immediate and sustained access to these medications. Objectives: To address lack of medication access for people with OUD, the Missouri Department of Mental Health began implementing a Medication First (Med First) treatment approach in its publicly-funded system of comprehensive substance use disorder treatment programs. Methods: This Perspective describes the four principles of Med First, which are based on evidence-based guidelines. It draws conceptual comparisons between the Housing First approach to chronic homelessness and the Med First approach to pharmacotherapy for OUD, and compares state certification standards for substance use disorder (SUD) treatment (the traditional approach) to Med First guidelines for OUD treatment. Finally, the Perspective details how Med First principles have been practically implemented. Results: Med First principles emphasize timely access to maintenance pharmacotherapy without requiring psychosocial services or discontinuation for any reason other than harm to the client. Early results regarding medication utilization and treatment retention are promising. Feedback from providers has been largely favorable, though clinical- and system-level obstacles to effective OUD treatment remain. Conclusion: Like the Housing First model, Medication First is designed to decrease human suffering and activate the strengths and capacities of people in need. It draws on decades of research and facilitates partnerships between psychosocial and medical treatment providers to offer effective and life-saving care to persons with OUD.

Applying Structural Systems Thinking to Frame Perspectives on Social Work Innovation.

OBJECTIVE: Innovation will be key to the success of the Grand Challenges Initiative in social work. A structural systems framework based in system dynamics could be useful for considering how to advance innovation. METHOD: Diagrams using system dynamics conventions were developed to link common themes across concept papers written by social work faculty members and graduate students (N = 19). RESULTS: Transdisciplinary teams and ethical partnerships with communities and practitioners will be needed to responsibly develop high-quality innovative solutions. A useful next step would be to clarify to what extent factors that could "make or break" these partnerships arise from within versus outside of the field of social work and how this has changed over time. CONCLUSIONS: Advancing innovation in social work will mean making decisions in a complex, ever-changing system. Principles and tools from methods that account for complexity, such as system dynamics, can help improve this decision-making process.

Substance use among persons with homeless experience in primary care.

BACKGROUND: Community survey data suggest high prevalence of substance use disorders among currently homeless individuals. There are less data regarding illicit drug and alcohol use problems of homeless-experienced persons engaged in primary care. They may have less severe use and require different care responses from primary care teams. METHODS: The authors surveyed currently and formerly homeless, i.e., homeless-experienced, persons engaged in primary care at five federally funded programs in the United States, administering the World Health Organization (WHO) Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). The ASSIST definitions of lower, moderate, and high risk were used to assess a spectrum of lifetime and recent substance use, from any use to likely dependence, and to identify sociodemographic and health status characteristics associated with severity of use. RESULTS: Almost one half of the sample (N = 601) had recently (within the past three months) used alcohol, and one third had recently used an illicit drug. The most commonly used illicit drugs in the past three months were cannabis (19%), cocaine (16%), and opioids (7.5%). Over one half (59%) of respondents had ASSIST-defined moderate- or high-risk substance use. A significant proportion (31%) of those identified as at moderate risk had no recent substance use, but did report past problematic use. Ten percent of the lower-risk group had past problematic use of alcohol. Severity of use was associated with worse health status, but not with housing status or type of homelessness experienced. CONCLUSIONS: Less severe (moderate-risk) use and past problematic use, potentially indicative of remitted substance use disorders, were more common than high-risk use in this primary care, homeless-experienced sample. These findings highlight the urgency of identifying effective ways to reduce risky substance use and prevent relapse in homeless-experienced persons.

Development of the Primary Care Quality-Homeless (PCQ-H) instrument: a practical survey of homeless patients' experiences in primary care.

BACKGROUND: Homeless patients face unique challenges in obtaining primary care responsive to their needs and context. Patient experience questionnaires could permit assessment of patient-centered medical homes for this population, but standard instruments may not reflect homeless patients' priorities and concerns. OBJECTIVES: This report describes (a) the content and psychometric properties of a new primary care questionnaire for homeless patients; and (b) the methods utilized in its development. METHODS: Starting with quality-related constructs from the Institute of Medicine, we identified relevant themes by interviewing homeless patients and experts in their care. A multidisciplinary team drafted a preliminary set of 78 items. This was administered to homeless-experienced clients (n=563) across 3 VA facilities and 1 non-VA Health Care for the Homeless Program. Using Item Response Theory, we examined Test Information Function (TIF) curves to eliminate less informative items and devise plausibly distinct subscales. RESULTS: The resulting 33-item instrument (Primary Care Quality-Homeless) has 4 subscales: Patient-Clinician Relationship (15 items), Cooperation among Clinicians (3 items), Access/Coordination (11 items), and Homeless-specific Needs (4 items). Evidence for divergent and convergent validity is provided. TIF graphs showed adequate informational value to permit inferences about groups for 3 subscales (Relationship, Cooperation, and Access/Coordination). The 3-item Cooperation subscale had lower informational value (TIF<5) but had good internal consistency (α=0.75) and patients frequently reported problems in this aspect of care. CONCLUSIONS: Systematic application of qualitative and quantitative methods supported the development of a brief patient-reported questionnaire focused on the primary care of homeless patients and offers guidance for future population-specific instrument development.

Measuring Attitudes Towards Empirically Supported Treatment in Real World Addiction Services.

Mental health workers with favorable attitudes toward empirically supported treatments (ESTs) are more likely to break through implementation barriers. The Evidence-Based Practice Attitudes Scale has been shown to be reliable for mental health workers, but has not been validated with addiction workers. This study investigates the use of the scale with a convenience sample of addiction workers from four agencies in one city. Results show that compared to mental health providers, addiction workers were more likely to view ESTs favorably if they were mandated and intuitively appealing. They also tended to rely more heavily on practical experience in forming attitudes toward treatment options. These results may help addiction agencies understand which types of workers are more likely to implement ESTs and inform effective engagement approaches specific to addiction workers.

State Mandates On Naloxone Coprescribing Associated With Short-Term Increase In Naloxone Codispensing.

In the midst of the opioid crisis in the US, efforts to mitigate overdose risks have become paramount, leading some states to introduce mandates for coprescribing the life-saving overdose reversal drug naloxone. These mandates were designed to specifically address people receiving opioid analgesics who had an elevated risk for overdose. This included people receiving high opioid dosages, those concurrently using benzodiazepines, or those with a history of substance use disorder or overdose. Using a nationally representative, multipayer cohort of patients receiving prescription opioids, we investigated how naloxone codispensing rates changed at the state level from 2016 to 2021 among patients with an elevated risk for overdose. Then we used controlled interrupted time series analyses to assess mandates' longitudinal impact on naloxone codispensing in ten states that implemented mandates. We observed an immediate and significant increase in the naloxone codispensing rates in eight states after the implementation of mandates. Nevertheless, in five of these states, the codispensing rates exhibited a subsequent downward trend after the initial increase. State mandates show potential for improving naloxone codispensing; however, mandates alone might not be adequate for sustained change. Further research is needed to identify strategies complementing and enhancing the impact of mandates in combating the overdose crisis.

Improving Estimates of the Prevalence of Opioid Use Disorder in the United States: Revising Keyes et al.

OBJECTIVES: The United States faces an ongoing drug overdose crisis, but accurate information on the prevalence of opioid use disorder (OUD) remains limited. A recent analysis by Keyes et al used a multiplier approach with drug poisoning mortality data to estimate OUD prevalence. Although insightful, this approach made stringent and partly inconsistent assumptions in interpreting mortality data, particularly synthetic opioid (SO)-involved and non-opioid-involved mortality. We revise that approach and resulting estimates to resolve inconsistencies and examine several alternative assumptions. METHODS: We examine 4 adjustments to Keyes and colleagues' estimation approach: (A) revising how the equations account for SO effects on mortality, (B) incorporating fentanyl prevalence data to inform estimates of SO lethality, (C) using opioid-involved drug poisoning data to estimate a plausible range for OUD prevalence, and (D) adjusting mortality data to account for underreporting of opioid involvement. RESULTS: Revising the estimation equation and SO lethality effect (adj. A and B) while using Keyes and colleagues' original assumption that people with OUD account for all fatal drug poisonings yields slightly higher estimates, with OUD population reaching 9.3 million in 2016 before declining to 7.6 million by 2019. Using only opioid-involved drug poisoning data (adj. C and D) provides a lower range, peaking at 6.4 million in 2014-2015 and declining to 3.8 million in 2019. CONCLUSIONS: The revised estimation equation presented is feasible and addresses limitations of the earlier method and hence should be used in future estimations. Alternative assumptions around drug poisoning data can also provide a plausible range of estimates for OUD population.

Comparing homeless persons' care experiences in tailored versus nontailored primary care programs.

OBJECTIVES: We compared homeless patients' experiences of care in health care organizations that differed in their degree of primary care design service tailoring. METHODS: We surveyed homeless-experienced patients (either recently or currently homeless) at 3 Veterans Affairs (VA) mainstream primary care settings in Pennsylvania and Alabama, a homeless-tailored VA clinic in California, and a highly tailored non-VA Health Care for the Homeless Program in Massachusetts (January 2011-March 2012). We developed a survey, the "Primary Care Quality-Homeless Survey," to reflect the concerns and aspirations of homeless patients. RESULTS: Mean scores at the tailored non-VA site were superior to those from the 3 mainstream VA sites (P < .001). Adjusting for patient characteristics, these differences remained significant for subscales assessing the patient-clinician relationship (P < .001) and perceptions of cooperation among providers (P = .004). There were 1.5- to 3-fold increased odds of an unfavorable experience in the domains of the patient-clinician relationship, cooperation, and access or coordination for the mainstream VA sites compared with the tailored non-VA site; the tailored VA site attained intermediate results. CONCLUSIONS: Tailored primary care service design was associated with a superior service experience for patients who experienced homelessness.

The association between longitudinal trends in receipt of buprenorphine for opioid use disorder and buprenorphine-waivered providers in the United States.

AIMS, DESIGN AND SETTING: We sought to describe longitudinal trends in buprenorphine receipt and buprenorphine-waivered providers in the United States from 2003 to 2021 and measure whether the relationship between the two differed after capacity-building strategies were enacted nationally in 2017. This was a retrospective study of two separate cohorts covering the years 2003-21, testing whether the association between two trends in these cohorts changed comparing 2003 to 2016 and from 2017 to 2021, among buprenorphine providers in the United States, regardless of treatment setting. Patients receiving dispensed buprenorphine at retail pharmacies. PARTICIPANTS: All providers who have obtained a waiver to prescribe buprenorphine in the United States, and an estimate of the annual number of patients who had buprenorphine for opioid use disorder (OUD) dispensed to them at a retail pharmacy. MEASUREMENTS: We synthesized and summarized data from multiple sources to assess the cumulative number of buprenorphine-waivered providers over time. We used national-level prescription data from IQVIA to estimate annual buprenorphine receipt for OUD. FINDINGS: From 2003 to 2021, the number of buprenorphine-waivered providers in the United States increased from fewer than 5000 in the first 2 years of Food and Drug Administration (FDA) approval to more than 114 000 in 2021, while patients receiving buprenorphine products for OUD increased from approximately 19 000 to more than 1.4 million. The strength of association between waivered providers and patients is significantly different before and after 2017 (P < 0.001). From 2003 to 2016, for each additional provider, there was an average increase of 32.1 [95% confidence interval (CI) = 28.7-35.6] patients, but an increase of only 4.6 (95% CI= 3.5-5.7) patients for each additional provider, beginning in 2017. CONCLUSIONS: In the United States, the relationship between the rates of growth in buprenorphine providers and patients became weaker after 2017. While efforts to increase buprenorphine-waivered providers were successful, there was less success in translating that into significant increases in buprenorphine receipt.

Enumerating contributions of fentanyls and other factors to the unprecedented 2020 rise in opioid overdose deaths: model-based analysis.

In 2020, the ongoing US opioid overdose crisis collided with the emerging COVID-19 pandemic. Opioid overdose deaths (OODs) rose an unprecedented 38%, due to a combination of COVID-19 disrupting services essential to people who use drugs, continued increases in fentanyls in the illicit drug supply, and other factors. How much did these factors contribute to increased OODs? We used a validated simulation model of the opioid overdose crisis, SOURCE, to estimate excess OODs in 2020 and the distribution of that excess attributable to various factors. Factors affecting OODs that could have been disrupted by COVID-19, and for which data were available, included opioid prescribing, naloxone distribution, and receipt of medications for opioid use disorder. We also accounted for fentanyls' presence in the heroin supply. We estimated a total of 18,276 potential excess OODs, including 1,792 lives saved due to increases in buprenorphine receipt and naloxone distribution and decreases in opioid prescribing. Critically, growth in fentanyls drove 43% (7,879) of the excess OODs. A further 8% is attributable to first-ever declines in methadone maintenance treatment and extended-released injectable naltrexone treatment, most likely due to COVID-19-related disruptions. In all, 49% of potential excess OODs remain unexplained, at least some of which are likely due to additional COVID-19-related disruptions. While the confluence of various COVID-19-related factors could have been responsible for more than half of excess OODs, fentanyls continued to play a singular role in excess OODs, highlighting the urgency of mitigating their effects on overdoses.

Long-Term Effects of Increasing Buprenorphine Treatment Seeking, Duration, and Capacity on Opioid Overdose Fatalities: A Model-based Analysis.

OBJECTIVES: Because buprenorphine treatment of opioid use disorder reduces opioid overdose deaths (OODs), expanding access to care is an important policy and clinical care goal. Policymakers must choose within capacity limitations whether to expand the number of people with opioid use disorder who are treated or extend duration for existing patients. This inherent tradeoff could be made less acute with expanded buprenorphine treatment capacity. METHODS: To inform such decisions, we used a validated simulation model to project the effects of increasing buprenorphine treatment-seeking, average episode duration, and capacity (patients per provider) on OODs in the United States from 2023 to 2033, varying the start time to assess the effects of implementation delays. RESULTS: Results show that increasing treatment duration alone could cost lives in the short term by reducing capacity for new admissions yet save more lives in the long term than accomplished by only increasing treatment seeking. Increasing provider capacity had negligible effects. The most effective 2-policy combination was increasing capacity and duration simultaneously, which would reduce OODs up to 18.6% over a decade. By 2033, the greatest reduction in OODs (≥20%) was achieved when capacity was doubled and average duration reached 2 years, but only if the policy changes started in 2023. Delaying even a year diminishes the benefits. Treatment-seeking increases were equally beneficial whether they began in 2023 or 2025 but of only marginal benefit beyond what capacity and duration achieved. CONCLUSIONS: If policymakers only target 2 policies to reduce OODs, they should be to increase capacity and duration, enacted quickly and aggressively.

To Prescribe or Not to Prescribe?: Barriers and Motivators for Progressing Along Each Stage of the Buprenorphine Training and Prescribing Path.

This study aimed to identify the strongest barriers and motivators associated with each step toward buprenorphine prescribing (1. obtaining a waiver, 2. beginning to prescribe, and 3. prescribing to more people) among a sample of Missouri-based medical professionals (N = 130). Item weights (number of endorsements times mean rank of the item's importance) were calculated based on their responses. Across groups, lack of access to psychosocial support services, need for higher levels of care, and clinical complexity were strong barriers. Among non-prescribers (n = 57, 46.3%), administrative burden, potential of becoming an addiction clinic, and concern about misuse and diversion were most heavily weighted. Among prescribers (n = 66, 53.7%), patients' inability to afford medications was a barrier across phases. Prominent motivators among all groups were the effectiveness of buprenorphine, improvement in other health outcomes, and a personal interest in treating addiction. Only prescribers reported the presence of institutional support and mentors as significant motivators.

Cost-effectiveness of Increasing Buprenorphine Treatment Initiation, Duration, and Capacity Among Individuals Who Use Opioids.

Importance: Buprenorphine is an effective and cost-effective medication to treat opioid use disorder (OUD), but is not readily available to many people with OUD in the US. The current cost-effectiveness literature does not consider interventions that concurrently increase buprenorphine initiation, duration, and capacity. Objective: To conduct a cost-effectiveness analysis and compare interventions associated with increased buprenorphine treatment initiation, duration, and capacity. Design and Setting: This study modeled the effects of 5 interventions individually and in combination using SOURCE, a recent system dynamics model of prescription opioid and illicit opioid use, treatment, and remission, calibrated to US data from 1999 to 2020. The analysis was run during a 12-year time horizon from 2021 to 2032, with lifetime follow-up. A probabilistic sensitivity analysis on intervention effectiveness and costs was conducted. Analyses were performed from April 2021 through March 2023. Modeled participants included people with opioid misuse and OUD in the US. Interventions: Interventions included emergency department buprenorphine initiation, contingency management, psychotherapy, telehealth, and expansion of hub-and-spoke narcotic treatment programs, individually and in combination. Main Outcomes and Measures: Total national opioid overdose deaths, quality-adjusted life years (QALYs) gained, and costs from the societal and health care perspective. Results: Projections showed that contingency management expansion would avert 3530 opioid overdose deaths over 12 years, more than any other single-intervention strategy. Interventions that increased buprenorphine treatment duration initially were associated with an increased number of opioid overdose deaths in the absence of expanded treatment capacity. With an incremental cost- effectiveness ratio of $19 381 per QALY gained (2021 USD), the strategy that expanded contingency management, hub-and-spoke training, emergency department initiation, and telehealth was the preferred strategy for any willingness-to-pay threshold from $20 000 to $200 000/QALY gained, as it was associated with increased treatment duration and capacity simultaneously. Conclusion and Relevance: This modeling analysis simulated the effects of implementing several intervention strategies across the buprenorphine cascade of care and found that strategies that were concurrently associated with increased buprenorphine treatment initiation, duration, and capacity were cost-effective.

Impacts of alcohol and opioid polysubstance use on road safety: Systematic review.

Connections between substance use, impairment, and road safety have been frequently researched. Yet, little is known about how simultaneous use of opioids and alcohol affects road safety outcomes, which is an increasingly critical link within the current landscape of the substance use environment and public health. Lack of this understanding is partly due to testing complications and data limitations. We define polysubstance use here as alcohol and opioids consumed together or within a small-time window such that both are present in the system. This polysubstance use is on the rise and produces greater health risks than when the substances are consumed separately. Given the increasing rate of opioid use, high prevalence of alcohol use, and dangers of polysubstance use, we aim to synthesize literature on the prevalence and impact of this polysubstance on road safety-related outcomes. We performed a systematic review of studies published between 1974 and 2020 that examined opioid and alcohol use exposures and road safety-related outcomes. Out of 644 initial findings, 20 studies were included in this review. Outcomes included motor vehicle crash injuries, deaths, or driver culpability; suspected driving under the influence; and simulated driving performance. Evidence from multiple sources showed a significant rise, approximately 1% to 7%, in the prevalence of opioids among fatally injured drivers in the U.S. from 1995 to 2016. Information published on the simultaneous presence of opioids and alcohol in people involved in crashes was scarce. The limited available findings point toward an overlap where up to 30% of opioid-positive people involved in a crash were also positive for alcohol. Studies also suggest a possibly elevated risk presented by this polysubstance use relative to the substances used alone, though the majority of identified studies did not estimate this association. The synthesized research indicates that alcohol and opioid use is not uncommon and may be increasing among people involved in adverse driving events. More research and better data are needed to improve estimates of association with road traffic-related outcomes, potentially improving substance testing in current surveillance systems or using linked data sets and other novel data sources to improve estimates.

Identifying and Characterizing Medical Advice-Seekers on a Social Media Forum for Buprenorphine Use.

Background: Online communities such as Reddit can provide social support for those recovering from opioid use disorder. However, it is unclear whether and how advice-seekers differ from other users. Our research addresses this gap by identifying key characteristics of r/suboxone users that predict advice-seeking behavior. Objective: The objective of this analysis is to identify and describe advice-seekers on Reddit for buprenorphine-naloxone use using text annotation, social network analysis, and statistical modeling techniques. Methods: We collected 5258 posts and their comments from Reddit between 2014 and 2019. Among 202 posts which met our inclusion criteria, we annotated each post to determine which were advice-seeking (n = 137) or not advice-seeking (n = 65). We also annotated each posting user's buprenorphine-naloxone use status (current versus formerly taking and, if currently taking, whether inducting or tapering versus other stages) and quantified their connectedness using social network analysis. To analyze the relationship between Reddit users' advice-seeking and their social connectivity and medication use status, we constructed four models which varied in their inclusion of explanatory variables for social connectedness and buprenorphine use status. Results: The stepwise model containing "total degree" (p = 0.002), "using: inducting/tapering" (p < 0.001), and "using: other" (p = 0.01) outperformed all other models. Reddit users with fewer connections and who are currently using buprenorphine-naloxone are more likely to seek advice than those who are well-connected and no longer using the medication, respectively. Importantly, advice-seeking behavior is most accurately predicted using a combination of network characteristics and medication use status, rather than either factor alone. Conclusions: Our findings provide insights for the clinical care of people recovering from opioid use disorder and the nature of online medical advice-seeking overall. Clinicians should be especially attentive (e.g., through frequent follow-up) to patients who are inducting or tapering buprenorphine-naloxone or signal limited social support.