Predictors of non-fatal overdose among a cohort of polysubstance-using injection drug users

Improving racial/ethnic health equity and naloxone access among people at risk for opioid overdose: A simulation modeling analysis of community-based naloxone distribution strategies in Massachusetts, United States

BACKGROUND AND AIMS

During the COVID-19 pandemic, there was a surge in opioid overdose deaths (OODs) in Massachusetts, USA, particularly among Black and Hispanic/Latinx populations. Despite the increasing racial and ethnic disparities in OODs, there was no compensatory increase in naloxone distributed to these groups. We aimed to evaluate two community-based naloxone expansion strategies, with the objective of identifying approaches that could mitigate mortality and racial and ethnic disparities in OODs.

DESIGN

Individual-based simulation model. We measured naloxone availability using naloxone kits per OOD and evaluated scenarios of achieving higher benchmarks for naloxone availability (i.e. 40, 60 and 80 kits per OOD) from 2022 levels (overall: 26.0, White: 28.8, Black: 17.3, Hispanic/Latinx: 18.9). We compared two naloxone distribution strategies: (1) proportional distribution: achieving the benchmark ratio at the overall population level while distributing additional kits proportional to the 2022 level for each racial/ethnic group (at 40 kits per OOD benchmark: overall: 40, White: 44.3, Black: 26.6, Hispanic/Latinx: 29.1), and (2) equity-focused distribution: achieving the benchmark ratio among each racial/ethnic group (at 40 kits per OOD benchmark: 40 for all groups).

SETTING

Massachusetts, United States.

PARTICIPANTS

People at risk of OOD.

MEASUREMENTS

Annual number and rate of OODs, total healthcare costs of increasing naloxone availability.

FINDINGS

Both naloxone distribution strategies yielded comparable predicted reductions in total OODs in 2025 and incurred similar incremental costs. However, the relative reduction in the rate of OODs differed across groups. For achieving an 80 kits per OOD benchmark, proportional distribution resulted in a projected 6.7%, 6.5% and 7.1% reduction in annual OODs in 2025 among White, Black and Hispanic/Latinx populations, respectively. In contrast, equity-focused distribution achieved a reduction of 5.7%, 11.3% and 10.2% in the respective groups. In all scenarios, the cost per OOD averted was lower than the generally accepted thresholds for cost per life saved.

CONCLUSIONS

An equity-focused naloxone distribution strategy designed to reduce racial and ethnic disparities in naloxone availability could improve health equity among racial and ethnic groups while potentially improving overall population health at lower healthcare costs per opioid overdose death averted than a proportional distribution strategy.

Drug overdose deaths among homeless veterans in the United States Department of Veterans Affairs healthcare system

BACKGROUND AND AIMS

With an epidemic of drug overdoses, contemporary research is needed to examine drug overdose deaths among homeless populations. This study measured rates, types and correlates of drug overdose deaths occurring over a 5-year study period among veterans experiencing homelessness (VEH) and non-homeless veterans (NHV) in the US Department of Veterans Affairs (VA) healthcare system.

DESIGN

Retrospective cohort study.

SETTING

USA.

PARTICIPANTS

A total of 6 128 921 veterans. We followed 399 125 VEH and 5 729 796 NHV between 2017 and 2021 using linked administrative VA and National Death Index data.

MEASUREMENTS

Multivariable Cox regression models were constructed to estimate hazard ratios (HRs) for homelessness as a predictor of time-to-occurrence of overdose deaths with 95% confidence interval (CIs), sequentially controlling for demographic, medical, substance use and mental health characteristics.

FINDINGS

Among overdose deaths, 8653 [93.7%, 95% confidence interval (CI) = 93.2-94.2%] were unintentional and 5378 (57.8%, 95% CI = 56.8-58.8%) involved opioids. The overdose-specific mortality rate (per 100 000 person-years) was 227.3 among VEH and 23.2 among NHV (HR = 9.76, 95% CI = 9.36, 10.16), with rates 7-14 times higher among VEH than NHV, depending on the drug involved. In fully adjusted models, homelessness was associated with greater risk of drug overdose death (HR = 3.33, 95% CI = 3.18, 3.49), with the greatest risk involving psychostimulants (HR = 4.19), followed by antiepileptic/sedative/hypnotic drugs (HR = 3.69), synthetic opioids (HR = 3.50) and natural and semi-synthetic opioids (HR = 2.79).

CONCLUSIONS

US veterans experiencing homelessness appear to have three times the risk for drug overdose deaths than non-homeless veterans. There may be specific risks associated with psychostimulant, antiepileptic, sedative and hypnotic drugs in this population that deserve greater attention.

The impact of an unsanctioned compassion club on non-fatal overdose

OBJECTIVES

In 2022, the Drug User Liberation Front opened an unsanctioned compassion club in Vancouver where members could purchase illicit drugs that had been rigorously tested to ensure quality and a lack of potentially fatal contaminants. We sought to evaluate the impact of access to this novel safer supply intervention on non-fatal overdose.

METHODS

Data were obtained from 47 club members via surveys completed at 3-month intervals between August 2022 and October 2023. We conducted multivariable generalized estimating equations (GEE) analyses to examine the association between club enrolment and the outcomes of: (1) any non-fatal overdose; and (2) any non-fatal overdose involving naloxone administration.

RESULTS

The final sample, including 47 study participants, contributed a total of 225 observations and 44.4 person-years of follow-up during the study, and a median follow-up duration of 12.2 months (quartile 1 - 3: 10.4 - 14.7) per participant. In multivariable GEE analyses, enrolment in the compassion club was associated with reduced likelihood of non-fatal overdose (Adjusted Odds Ratio [AOR] = 0.51, 95% Confidence Interval (CI): 0.26 - 0.99) and non-fatal overdose involving naloxone administration (AOR = 0.37, 95% CI: 0.16 - 0.84) after adjusting for potential confounders.

DISCUSSION

In this study, enrolment in an unsanctioned compassion club was found to be associated with reductions in any type of non-fatal overdose and non-fatal overdose involving naloxone administration. These findings highlight the need for ongoing research on safer supply interventions, as well as the potential of non-medicalized compassion clubs to complement existing safer supply programming and reduce overdose events.

Relationship between opioid cross-tolerance during buprenorphine stabilization and return to opioid use during buprenorphine dose tapering

RATIONALE

Opioid injection drug use (IDU) has been linked to a more severe pattern of use (e.g. tolerance, overdose risk) and shorter retention in treatment, which may undermine abstinence attempts.

OBJECTIVES

This secondary data analysis of four human laboratory studies investigated whether current opioid IDU modulates subjective abuse liability responses to high-dose hydromorphone during intermediate-dose buprenorphine stabilization (designed to suppress withdrawal but allow surmountable agonist effects), and whether hydromorphone response magnitude predicts latency of return to opioid use during buprenorphine dose-tapering.

METHODS

Regular heroin users not currently seeking treatment (n = 54; 29 current injectors, 25 non-injectors) were stabilized on 8-mg/day sublingual buprenorphine and assessed for subjective responses (e.g. 'liking', craving) to hydromorphone 24-mg intramuscular challenge (administered 16-hr post-buprenorphine) under randomized, double-blinded, controlled conditions. A subgroup (n = 35) subsequently completed a standardized 3-week outpatient buprenorphine dose-taper, paired with opioid-abstinent contingent reinforcement, and were assessed for return to opioid use based on thrice-weekly urinalysis and self-report.

RESULTS

During buprenorphine stabilization, IDU reported lower 'liking' of buprenorphine and post-hydromorphone peak 'liking', 'good effect' and 'high' compared to non-IDU. Less hydromorphone peak increase-from-baseline in 'liking' (which correlated with less hydromorphone-induced craving suppression) predicted significantly faster return to opioid use during buprenorphine dose-tapering.

CONCLUSIONS

In these buprenorphine-stabilized regular heroin users, IDU is associated with attenuated 'liking' response (more cross-tolerance) to buprenorphine and to high-dose hydromorphone challenge and, in turn, this cross-tolerance (but not IDU) predicts faster return to opioid use. Further research should examine mechanisms that link cross-tolerance to treatment response.

Correlates of overdose among 2711 people who use drugs and live in 7 rural US sites

BACKGROUND

Overdose rates in rural areas have been increasing globally, with large increases in the United States. Few studies, however, have identified correlates of non-fatal overdose among rural people who use drugs (PWUD). The present analysis describes correlates of nonfatal overdose among a large multistate sample of rural PWUD.

METHODS

This is a cross-sectional analysis of data gathered via surveys with PWUD recruited through seven Rural Opioid Initiative (ROI) sites. Descriptive analyses were conducted to assess the prevalence of past 30-day overdose. Generalized estimating equations were used to estimate a series of multivariable models quantifying relationships of select factors to past-month overdose; factors were selected using the Risk Environment Framework.

RESULTS

The multisite sample included 2711 PWUD, 6% of whom reported overdosing in the past 30 days. In the fully adjusted model, houselessness (AOR=2.27, 95%CI[1.48, 3.48]), a positive test result for Hepatitis C infection (AOR=1.73 95%CI[1.18, 2.52]) and heroin/fentanyl use (AOR= 8.58 95%CI [3.01, 24.50]) were associated with an increased risk of reporting past 30-day overdose, while having a high-school education or less was associated with reduced odds of overdose (AOR=0.52, 95% CI[0.37, 0.74]).

CONCLUSION

As in urban areas, houselessness, Hepatitis C infection, and the use of heroin and fentanyl were significant correlates of overdose. Widespread access to overdose prevention interventions - including fentanyl test strips and naloxone - is critical in this rural context, with particular outreach needed to unhoused populations, people living with Hepatitis C, and people using opioids.

Psychosocial factors associated with overdose subsequent to Illicit Drug use: a systematic review and narrative synthesis

BACKGROUND AND AIMS

Psychological and social status, and environmental context, may mediate the likelihood of experiencing overdose subsequent to illicit drug use. The aim of this systematic review was to identify and synthesise psychosocial factors associated with overdose among people who use drugs.

METHODS

This review was registered on Prospero (CRD42021242495). Systematic record searches were undertaken in databases of peer-reviewed literature (Medline, Embase, PsycINFO, and Cinahl) and grey literature sources (Google Scholar) for work published up to and including 14 February 2023. Reference lists of selected full-text papers were searched for additional records. Studies were eligible if they included people who use drugs with a focus on relationships between psychosocial factors and overdose subsequent to illicit drug use. Results were tabulated and narratively synthesised.

RESULTS

Twenty-six studies were included in the review, with 150,625 participants: of those 3,383-4072 (3%) experienced overdose. Twenty-one (81%) studies were conducted in North America and 23 (89%) reported polydrug use. Psychosocial factors associated with risk of overdose (n = 103) were identified and thematically organised into ten groups. These were: income; housing instability; incarceration; traumatic experiences; overdose risk perception and past experience; healthcare experiences; perception of own drug use and injecting skills; injecting setting; conditions with physical environment; and social network traits.

CONCLUSIONS

Global rates of overdose continue to increase, and many guidelines recommend psychosocial interventions for dependent drug use. The factors identified here provide useful targets for practitioners to focus on at the individual level, but many identified will require wider policy changes to affect positive change. Future research should seek to develop and trial interventions targeting factors identified, whilst advocacy for key policy reforms to reduce harm must continue.

The relationship between felt stigma and non-fatal overdose among rural people who use drugs

BACKGROUND

Drug overdose deaths in the United States exceeded 100,000 in 2021 and 2022. Substance use stigma is a major barrier to treatment and harm reduction utilization and is a priority target in ending the overdose epidemic. However, little is known about the relationship between stigma and overdose, especially in rural areas. We aimed to characterize the association between felt stigma and non-fatal overdose in a multi-state sample of rural-dwelling people who use drugs.

METHODS

Between January 2018 and March 2020, 2,608 people reporting past 30-day opioid use were recruited via modified chain-referral sampling in rural areas across 10 states. Participants completed a computer-assisted survey of substance use and substance-related attitudes, behaviors, and experiences. We used multivariable logistic regression with generalized estimating equations to test the association between felt stigma and recent non-fatal overdose.

RESULTS

6.6% of participants (n = 173) reported an overdose in the past 30 days. Recent non-fatal overdose was significantly associated with felt stigma after adjusting for demographic and substance use-related covariates (aOR: 1.47, 95% CI: 1.20-1.81). The association remained significant in sensitivity analyses on component fear of enacted stigma items (aOR: 1.48, 95% CI: 1.20-1.83) and an internalized stigma item (aOR: 1.51, 95% CI: 1.07-2.14).

CONCLUSIONS

Felt stigma related to substance use is associated with higher risk of non-fatal overdose in rural-dwelling people who use drugs. Stigma reduction interventions and tailored services for those experiencing high stigma are underutilized approaches that may mitigate overdose risk.

Effects of a Two-Month Exercise Training Program on Concurrent Non-Opiate Substance Use in Opioid-Dependent Patients during Substitution Treatment

BACKGROUND

This randomized controlled trial aimed to evaluate the effects of a two-month exercise intervention on the concurrent non-opiate substance use (alcohol, cocaine, cannabis, and benzodiazepines) in opioid users during their medication treatment.

METHODS

Ninety opioid users (41 females) in methadone and buprenorphine medication treatment were randomly divided into four groups: (a) buprenorphine experimental (BEX; n = 26, aged 41.9 ± 6.1 yrs); (b) buprenorphine control (BCON; n = 25, aged 41.9 ± 5.6 yrs); (c) methadone experimental (MEX; n = 20, aged 46.7 ± 6.6 yrs); and (d) methadone control (MCON; n = 19, aged 46.1 ± 7.5 yrs). The experimental groups (BEX and MEX) followed an aerobic exercise training program on a treadmill for 20 min at 70% HRmax, 3 days/week for 8 weeks. Socio-demographic, anthropometric, and clinical characteristics, as well as non-opioid drug use in days and quantity per week, were assessed before and after the intervention period.

RESULTS

Following the exercise training, the weekly non-opioid substance consumption (days) decreased (p < 0.05) in both exercise groups and was lower in BEX compared to MEX, while no differences were observed (p > 0.05) between the control groups (BCON vs. MCON) or compared to their baseline levels. Similarly, the daily amount of non-opiate substance intake was reduced (p < 0.05) post-training in BEX and MEX, whereas it did not differ (p > 0.05) in BCON and MCON compared to the baseline.

CONCLUSIONS

The two-month exercise intervention reduced the non-opioid drug use in both the methadone and buprenorphine substitution groups compared to the controls, suggesting that aerobic exercise training may be an effective strategy for treating patients with OUDs.

Effect of modified income assistance payment schedules on substance use service access: Evidence from an experimental study

BACKGROUND

Despite being critical to reducing the impacts of poverty internationally, synchronized monthly government income assistance payments are linked to intensified drug use and associated harms, including disrupted access to substance use-related services. This study evaluates whether alternative income assistance distribution schedules improve harm reduction (HR), pharmacotherapy and substance use service utilization.

METHODS

This exploratory, parallel group, unblinded, randomized controlled trial analyzed data from adults (n = 192) in Vancouver, Canada receiving income assistance, and reporting active, regular illicit drug use. Participants were randomly assigned on a 1:2:2 basis for six income assistance payment cycles to: (1) existing government schedules (control); (2) a "staggered" single monthly payment; or (3) "split & staggered" twice-monthly payments. Generalized linear mixed models analyzed secondary outcomes of HR, pharmacotherapy and substance use service utilization as well as barriers accessing these services.

RESULTS

Forty-five control, 71 staggered, and 76 split & staggered volunteers participated between 2015 and 2019. Multivariable modified per-protocol analyses demonstrate increased access to substance use services (Adjusted Odds Ratio [AOR] 1.64, 95% Confidence Interval [CI] 1.02-2.64) for split & staggered arm participants, and, conversely, increased barriers to HR for participants in the staggered (AOR 2.34, 95% CI 1.24-4.41) and split & staggered (AOR 2.16, 95% CI 1.08-4.35) arms. Results also showed decreased barriers to pharmacotherapy around government payments (AOR 0.23, 95% CI 0.06-0.90), pharmacotherapy around individual payments (AOR 0.12, 95% CI 0.02-0.58), and HR around individual payments (AOR 0.11, 95% CI 0.02-0.63) for staggered arm participants.

CONCLUSION

Modifying payments schedules demonstrate improved access to overall substance use services, and reduced barriers to HR and pharmacotherapy around income assistance payments. However, increased overall barriers to HR access were also shown. These complex, predominantly beneficial findings support the exploration of offering alternative payment schedules to support service access.

Associations between stimulant use and return to illicit opioid use following initiation onto medication for opioid use disorder

AIM

The aim of this study was to estimate how ongoing stimulant use affects return to illicit opioid use after initiation onto medication for opioid use disorder (MOUD).

DESIGN

This was a secondary analysis of pooled data from two clinical trials comparing buprenorphine (BUP-NX) and extended-release naltrexone (XR-NTX).

SETTING

Thirteen opioid treatment programs and HIV clinics across 10 states in the United States from 2014 to 2019 took part in this study.

PARTICIPANTS

A total of 528 participants who initiated MOUD as part of trial participation were included. Nearly half (49%) were between 30 and 49 years of age, 69% were male and 66% were non-Hispanic White.

MEASUREMENTS

The primary outcome was first self-reported day of non-prescribed opioid use following MOUD initiation, and the exposure of interest was daily stimulant use (methamphetamine, amphetamines or cocaine). Both were defined using time-line follow-back. Among participants reporting at least 1 day of illicit opioid use, we also examined relapse to ongoing use, defined as (1) 7 days of continuous opioid use or (2) 4 consecutive weeks with self-reported opioid use, one or more positive urine drug screens (UDS) for opioids or one or more missing UDS.

FINDINGS

Forty-seven per cent of participants reported stimulant use following MOUD initiation, 58% returned to illicit opioid use and 66% of those relapsed to ongoing use. Stimulant use was strongly associated with increased risk of misusing opioids after MOUD initiation when measured daily [adjusted hazard ratio (aHR) = 9.23, 95% confidence interval (CI) = 6.80-12.50, P < 0.001] and over a 7-day period (aHR = 1.27 for each additional day, CI = 1.18-1.37, P < 0.001). Using stimulants weekly or more often was associated with increased likelihood of relapse to ongoing opioid use compared with less than weekly or no stimulant use (adjusted odds ratio = 2.30, CI = 1.05-5.39, P = 0.044).

CONCLUSIONS

People initiated on medication for opioid use disorder who subsequently use stimulants appear to be more likely to return to and continue using non-prescribed opioids compared with those without stimulant use. The association appears to be stronger among patients who initiate buprenorphine compared with those who initiate extended-release naltrexone.

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.

Correlates of nonfatal overdose among treatment-seeking individuals with non-heroin opioid use disorder: Findings from a pragmatic, pan-Canadian, randomized control trial

INTRODUCTION

Misuse of prescription and synthetic opioids is a primary contributor to the escalating overdose crisis in North America. However, factors associated with nonfatal overdose (NFO) in this context are poorly understood. We examined individual and socio-structural level correlates of NFO among treatment-seeking adults with an opioid use disorder (OUD) not attributed to heroin (nonheroin opioid use disorder [NH-OUD]).

METHODS

The study drew data from OPTIMA, a pan-Canadian, multicenter, pragmatic, two-arm randomized control trial comparing supervised methadone and flexible take-home dosing buprenorphine/naloxone models of care among adults with NH-OUD conducted between 2017 and 2020. We used bivariable and multivariable logistic regression to determine factors associated with a lifetime history of NFO among participants enrolled in the trial.

RESULTS

Of 267 included participants, 154 (58%) reported a NFO in their lifetime, of whom 83 (55 %) had an NFO in the last 6 months. In multivariable analyses, positive urine drug test (UDT) for methamphetamine/amphetamine (Adjusted Odds Ratio [AOR] = 2.59; 95 % confidence interval [CI]: 1.17-5.80), positive UDT for fentanyl (AOR = 2.31; 95 % CI: 1.01-5.30), receiving income assistance (AOR = 2.17; 95 % CI: 1.18-4.09) and homelessness (AOR = 2.40; 95 % CI: 1.25-4.68) were positively associated with a lifetime history of NFO.

CONCLUSIONS

We found a high prevalence of NFO history in treatment-seeking adults with NH-OUD, particularly among participants with certain drug use patterns and markers of socio-structural marginalization at the time of enrollment. Given the known impact of prior NFO on future harms, these findings highlight the need for comprehensive care approaches that address polysubstance use and social determinants of health to mitigate future overdose risk.

A call to action: Contingency management to improve post-release treatment engagement among people with opioid use disorder who are incarcerated

People with opioid use disorder (OUD) are overrepresented in US correctional facilities and experience disproportionately high risk for illicit opioid use and overdose after release. A growing number of correctional facilities offer medication for OUD (MOUD), which is effective in reducing these risks. However, a recent evaluation found that <50% of those prescribed MOUD during incarceration continued MOUD within 30 days after release, demonstrating a need to improve post-release continuity of care. We describe available evidence on contingency management (CM), an intervention wherein patients receive incentives contingent on behavior change, to achieve this goal. A prior systematic review reported strong evidence in support of CM for increasing treatment adherence in MOUD programs, but the trials reviewed did not include incarcerated participants. Research on CM to increase treatment adherence among participants in the criminal justice system is limited with mixed findings. However, in comparison to the trials that supported CM's efficacy in the community, CM trials in the criminal justice system provided smaller rewards with greater delays in the delivery of rewards to patients, which likely contributed to null findings. Indeed, a prior meta-analysis demonstrates a dose-response relationship between the magnitude and immediacy of reward and CM effectiveness. Thus, CM involving larger and more immediately delivered rewards are likely necessary to improve MOUD adherence during the critical period following release from incarceration. Future research on the effectiveness and implementation of CM to improve MOUD retention after release from incarceration is warranted.

Hippocampal volume loss in individuals with a history of non-fatal opioid overdose

Incidence of opioid-related overdoses in the United States has increased dramatically over the past two decades. Despite public emphasis on overdose fatalities, most overdose cases are not fatal. Although there are case reports of amnestic syndromes and acute injury to the hippocampus following non-fatal opioid overdose, the effects of such overdoses on brain structure are poorly understood. Here, we investigated the neuroanatomical correlates of non-fatal opioid overdoses by comparing hippocampal volume in opioid use disorder (OUD) patients who had experienced an opioid overdose (OD; N = 17) with those who had not (NOD; N = 32). Voxel-based morphometry showed lower hippocampal volume in the OD group than in the NOD group, which on post hoc analysis was evident in the left but not the right hippocampus. These findings strengthen the evidence that hippocampal injury is associated with non-fatal opioid overdose, which is hypothesized to underlie overdose-related amnestic syndrome.

The impact of the implementation of medication for opioid use disorder and COVID-19 in a statewide correctional system on treatment engagement, postrelease continuation of care, and overdose

BACKGROUND

People with opioid use disorder (OUD) are overrepresented in US correctional facilities and experience disproportionately high risk for overdose after release. Medications for OUD (MOUD) are highly efficacious but not available to most incarcerated individuals. In 2018, Vermont began providing MOUD for all incarcerated individuals with OUD statewide. In 2020, the COVID-19 state of emergency began. We assessed the impact of both events on MOUD utilization and treatment outcomes.

METHODOLOGY

Analyses linked Vermont Department of Corrections administrative data and Medicaid claims data between 07/01/2017 and 03/31/2021. The study used logistic regression to analyze treatment engagement among all incarcerated individuals in Vermont. Multilevel modeling assessed change in clinical outcomes among release episodes that occurred among individuals with an OUD diagnosis Medicaid claim.

RESULTS

Prescriptions for MOUD while incarcerated increased from 0.8% to 33.9% of the incarcerated population after MOUD implementation (OR = 67.4) and subsequently decreased with the onset of COVID-19 to 26.6% (OR = 0.7). After MOUD implementation, most prescriptions (63.1%) were to individuals who had not been receiving MOUD prior to incarceration, but this figure decreased to 53.9% with the onset of COVID-19 (OR = 0.7). Prescriptions for MOUD within 30 days after release increased from 33.9% of those with OUD before to 41.0% after MOUD implementation (OR = 1.4) but decreased to 35.6% with the onset of COVID-19 (OR = 0.8). Simultaneously, opioid-related nonfatal overdoses within 30 days after release decreased from 1.2% before to 0.8% after statewide MOUD implementation (OR = 0.3) but increased to 1.9% during COVID-19 (OR = 3.4). Fatal overdoses within 1 year after release decreased from 27 deaths before to ≤10 after statewide MOUD implementation and remained ≤10 during COVID-19.

CONCLUSIONS

This longitudinal evaluation demonstrated increased treatment engagement and a decrease in opioid-related overdose following implementation of MOUD in a statewide correctional system. In contrast, these improvements were somewhat attenuated with the onset of COVID-19, which was associated with decreased treatment engagement and an increase in nonfatal overdoses. Considered together, these findings demonstrate the benefits of statewide MOUD for incarcerated individuals as well as the need to identify and address barriers to continuation of care following release from incarceration in the context of COVID-19.

Factors associated with patient perceived suboptimal dosing of in-hospital opioid agonist therapy among people who use illicit drugs in Vancouver, Canada

Optimal dosing of opioid agonist therapy (OAT) is essential for treatment success. However, initiation and maintenance of OAT in hospital settings can be challenging given differing levels of opioid tolerance, withdrawal, and intoxication among patients.

The objective of this study was to characterize the prevalence and factors associated with in-hospital patient perceived suboptimal OAT dosing among people who use illicit drugs (PWUD) in Vancouver, Canada.

Data were derived from three prospective cohorts of PWUD in Vancouver, Canada. Bivariable and multivariable logistic regression models were used to examine factors associated with patient perceived suboptimal in-hospital OAT dose.

273 study participants were prescribed OAT while in hospital: 83 (30.4%) participants perceived their OAT dose to be suboptimal. In a multivariable model, factors positively associated with a perceived suboptimal OAT dose included: homelessness (adjusted odds ratio [AOR] = 2.85; 95% CI: 1.53-5.28), daily stimulant use (AOR = 2.03; 95% CI: 1.14-3.63) and illicit drug use while in hospital (AOR = 2.33; 95% CI: 1.31-4.16).

Almost one third of participants perceived receiving a suboptimal OAT dose while in hospital. These observed correlations indicate that a patient's perception of suboptimal OAT dosing in hospital may be more prevalent for patients who are homeless, report polysubstance use with stimulants and opioids and who obtain illicit drugs while hospitalized. While cautious prescribing of OAT in patients experiencing hospitalization is important, these findings demonstrate a high prevalence of and apparent risk factors for perceived suboptimal OAT dosing.

Syndemic factors associated with non-fatal overdose among young opioid users in New York City

Introduction

Rates of illicit opioid use are particularly high among young adults, yet research on overdose experience and factors associated with overdose in this population remains limited. This study examines the experiences and correlates of non-fatal overdose among young adults using illicit opioids in New York City (NYC).

Methods

539 participants were recruited via Respondent-Driven Sampling in 2014-2016. Eligibility criteria included: aged 18-29 years old; current residence in NYC; and nonmedical prescription opioid (PO) use and/or heroin use in the past 30 days. Participants completed structured interviews to assess their socio-demographics, drug use trajectories, current substance use and lifetime and most recent overdose experiences, and were tested on-site for hepatitis C virus (HCV) antibodies.

Results

43.9% of participants reported lifetime overdose experience; of these, 58.8% had experienced two or more overdose events. The majority of participants' most recent overdoses (63.5%) were due to polysubstance use. In bivariable analyses, after RDS adjustment, having ever overdosed was correlated with: household income of >$100,00 growing up (vs. $51,000-100,000); lifetime homelessness; HCV antibody-positive status; lifetime engagement in regular nonmedical benzodiazepine use, regular heroin injection and regular PO injection; and using a non-sterile syringe in the past 12 months. Multivariable logistic regression identified childhood household income >$100,00 (AOR=1.88), HCV-positive status (AOR=2.64), benzodiazepine use (AOR=2.15), PO injection (AOR=1.96) and non-sterile syringe use (AOR=1.70) as significant independent correlates of lifetime overdose. A multivariable model with multiple overdoses (vs. one) found only lifetime regular heroin use and PO injection to be strong correlates.

Discussion

Results indicate a high prevalence of lifetime and repeated overdose among opioid-using young adults in NYC, highlighting a need for intensified overdose prevention efforts for this population. The strong associations of HCV and indices of polydrug use with overdose suggest that prevention efforts should address the complex risk environment in which overdose occurs, attending to the overlapping nature of disease-related risk behavior and overdose risk behavior among young people who inject opioids. Overdose prevention efforts tailored for this group may find it useful to adopt a syndemic conception of overdose that understands such events as resulting from multiple, and often interrelated, risk factors.

A Novel Index Measure of Housing-related Risk as a Predictor of Overdose among Young People Who Inject Drugs and Injection Networks

Background

For people who inject drugs (PWID), housing instability due to decreasing housing affordability and other factors (e.g., loss of housing due to severed relational ties, evictions due to drug use) results in added pressure on an already vulnerable population. Research has shown that housing instability is associated with overdose risk among PWID. However, the construct of housing instability has often been operationalized as a single dimension (e.g., housing type, homelessness, transience). We propose a multi-dimensional measure of housing instability risk and examine its association with drug overdose to promote a more holistic examination of housing status as a predictor of overdose.

Methods

The baseline data from a network-based, longitudinal study of young PWID and their networks living in metropolitan Chicago, Illinois was analyzed to examine the relationship between a housing instability risk index-consisting of five dichotomous variables assessing housing instability-and lifetime overdose count using negative binomial regression.

Results

We found a significant positive association between the housing instability risk score and lifetime overdose count after adjusting for 12 variables.

Conclusions

Our results support the practical utility of a multi-dimensional measure of housing instability risk in predicting overdose and highlight the importance of taking a holistic approach to addressing housing instability when designing interventions.

The POP (Permanent Supportive Housing Overdose Prevention) Study: protocol for a hybrid type 3 stepped-wedge cluster randomized controlled trial

BACKGROUND

Permanent supportive housing (PSH)-subsidized housing paired with support services such as case management-is a key part of national strategic plans to end homelessness. PSH tenants face high overdose risk due to a confluence of individual and environmental risk factors, yet little research has examined overdose prevention in PSH.

METHODS

We describe the protocol for a hybrid type 3 stepped-wedge cluster randomized controlled trial (RCT) of overdose prevention practice implementation in PSH. We adapted evidence-based overdose prevention practices and implementation strategies for PSH using input from stakeholder focus groups. The trial will include 20 PSH buildings (with building size ranging from 20 to over 150 tenants) across New York City and New York's Capital Region. Buildings will be randomized to one of four 6-month intervention waves during which they will receive a package of implementation support including training in using a PSH Overdose Prevention (POP) Toolkit, time-limited practice facilitation, and learning collaboratives delivered to staff and tenant implementation champions appointed by each building. The primary outcome is building-level fidelity to a defined list of overdose prevention practices. Secondary and exploratory implementation and effectiveness outcomes will be examined using PSH staff and tenant survey questionnaires, and analysis of tenant Medicaid data. We will explore factors related to implementation success, including barriers and facilitators, using qualitative interviews with key stakeholders. The project is being conducted through an academic-community partnership, and an Advisory Board including PSH tenants and other key stakeholders will be engaged in all stages of the project.

DISCUSSION

We describe the protocol for a hybrid type 3 stepped-wedge cluster RCT of overdose prevention practice implementation in PSH. This study will be the first controlled trial of overdose prevention implementation in PSH settings. The research will make a significant impact by testing and informing future implementation strategies to prevent overdose for a population at particularly high risk for overdose mortality. Findings from this PSH-focused research are expected to be broadly applicable to other housing settings and settings serving people experiencing homelessness.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05786222 , registered 27 March 2023.

Budget impact tool for the incorporation of medications for opioid use disorder into jail/prison facilities

BACKGROUND

Given the personal and public consequences of untreated/undertreated OUD among persons involved in the justice system, an increasing number of jails and prisons are incorporating medication for opioid use disorder (MOUD) into their system. Estimating the costs of implementing and sustaining a particular MOUD program is vital to detention facilities, which typically face modest, fixed health care budgets. We developed a customizable budget impact tool to estimate the implementation and sustainment costs of numerous MOUD delivery models for detention facilities.

METHODS

The aim is to describe the tool and present an application of a hypothetical MOUD model. The tool is populated with resources required to implement and sustain various MOUD models in detention facilities. We identified resources via micro-costing techniques alongside randomized clinical trials. The resource-costing method is used to assign values to resources. Resources/costs are categorized as (a) fixed, (b) time-dependent, and (c) variable. Implementation costs include (a), (b), and (c) over a specified timeframe. Sustainment costs include (b) and (c). The MOUD model example entails offering all three FDA-approved medications, with methadone and buprenorphine provided by vendors, and naltrexone by the jail/prison facility.

RESULTS

Fixed resources/costs are incurred only once, including accreditation fees and trainings. Time-dependent resources/costs are recurring, but fixed over a given time-period; e.g., medication delivery and staff meetings. Variable resources/costs are those that are a direct function of the number of persons treated, such as the medication provided to each patient. Using nationally representative prices, we estimated fixed/sustainment costs to be $2919/patient, over 1 year. This article estimates annual sustainment costs to be $2885/patient.

CONCLUSION

The tool will serve as a valuable asset to jail/prison leadership, policymakers, and other stakeholders interested in identifying/estimating the resources and costs associated with alternative MOUD delivery models, from the planning stages through sustainment.

Estimating the impact of stimulant use on initiation of buprenorphine and extended-release naltrexone in two clinical trials and real-world populations

BACKGROUND

Co-use of stimulants and opioids is rapidly increasing. Randomized clinical trials (RCTs) have established the efficacy of medications for opioid use disorder (MOUD), but stimulant use may decrease the likelihood of initiating MOUD treatment. Furthermore, trial participants may not represent "real-world" populations who would benefit from treatment.

METHODS

We conducted a two-stage analysis. First, associations between stimulant use (time-varying urine drug screens for cocaine, methamphetamine, or amphetamines) and initiation of buprenorphine or extended-release naltrexone (XR-NTX) were estimated across two RCTs (CTN-0051 X:BOT and CTN-0067 CHOICES) using adjusted Cox regression models. Second, results were generalized to three target populations who would benefit from MOUD: Housed adults identifying the need for OUD treatment, as characterized by the National Survey on Drug Use and Health (NSDUH); adults entering OUD treatment, as characterized by Treatment Episodes Dataset (TEDS); and adults living in rural regions of the U.S. with high rates of injection drug use, as characterized by the Rural Opioids Initiative (ROI). Generalizability analyses adjusted for differences in demographic characteristics, substance use, housing status, and depression between RCT and target populations using inverse probability of selection weighting.

RESULTS

Analyses included 673 clinical trial participants, 139 NSDUH respondents (weighted to represent 661,650 people), 71,751 TEDS treatment episodes, and 1,933 ROI participants. The majority were aged 30-49 years, male, and non-Hispanic White. In RCTs, stimulant use reduced the likelihood of MOUD initiation by 32% (adjusted HR [aHR] = 0.68, 95% CI 0.49-0.94, p = 0.019). Stimulant use associations were slightly attenuated and non-significant among housed adults needing treatment (25% reduction, aHR = 0.75, 0.48-1.18, p = 0.215) and adults entering OUD treatment (28% reduction, aHR = 0.72, 0.51-1.01, p = 0.061). The association was more pronounced, but still non-significant among rural people injecting drugs (39% reduction, aHR = 0.61, 0.35-1.06, p = 0.081). Stimulant use had a larger negative impact on XR-NTX initiation compared to buprenorphine, especially in the rural population (76% reduction, aHR = 0.24, 0.08-0.69, p = 0.008).

CONCLUSIONS

Stimulant use is a barrier to buprenorphine or XR-NTX initiation in clinical trials and real-world populations that would benefit from OUD treatment. Interventions to address stimulant use among patients with OUD are urgently needed, especially among rural people injecting drugs, who already suffer from limited access to MOUD.

"It's just not the same": Exploring PWUD' perceptions of and experiences with drug policy and SCS services change in a Canadian City

BACKGROUND AND AIMS

Shifting political contexts can significantly alter drug policy approaches and available supports for People Who Use Drugs (PWUD). The purpose of this study was to explore how shifts in provincial drug policy approaches, specifically the replacement of a Safe Consumption Site (SCS) with a smaller mobile Overdose Prevention Site (OPS) in Lethbridge, Alberta Canada, impacted PWUD' access to and experiences with harm reduction services.

METHODS

We conducted semi-structured interviews with 50 PWUD in the City of Lethbridge, Canada. Through traditional fieldwork, we recruited participants within, and just outside of, downtown Lethbridge. Using a standardized general prompt guide to begin interviews, participants were asked a variety of questions about their experiences with and perceptions of SCS access and changes to SCS provisions. Interviews were audio recorded, then transcribed, coded, and analyzed.

RESULTS

Participants reported regular and frequent access and overall positive experiences with the SCS, despite also noting certain operational barriers (e.g., long wait times). By contrast, participants reported more limited use of the new OPS compared to the SCS because of three main reasons: (1) concerns about location; (2) smoking room elimination; and (3) lack of social space and activities. Overall, changes to SCS provision produced a range of negative consequences for PWUD in Lethbridge. These relate to perceived increases in drug-related harms (e.g., increased overdoses) as well as negative social impacts (e.g., lack of place to meet other people).

CONCLUSION

Findings from this study provide preliminary indications of the importance of understanding how contextual and locally-specific elements (location, limits on permitted route administration, and social aspects) can work together to facilitate SCS uptake and even overcome traditional SCS barriers. Conversely, the absence of such elements can hinder SCS uptake. Results show that the value of SCS might differ across locations, pointing to the need for further locally-grounded examinations of harm reduction service uptake and experience.

City streetscapes and neighborhood characteristics of fatal opioid overdoses among people experiencing homelessness who use drugs in New York City, 2017-2019

BACKGROUND

While housing is a critical social determinant of nonprescription opioid overdose, little is known about how place impacts fatal overdose for people experiencing homelessness (PEH) who use drugs beyond the public versus private domains. This study investigated patterns of neighborhood environment features at locations of fatal overdoses among PEH.

METHODS

We remotely visited locations of opioid-involved fatal overdoses provided by the New York City Office of the Chief Medical Examiner, 2017-2019 (n=3276), with Google Street View and used systematic social observation to assess characteristics of the street block related to drug exposures. We cross-referenced home address with city shelters and supportive housing to identify PEH (n=503). We used the differences of K functions from the spatial point patterns and kernel ratio function maps to identify geographic clusters. We then used logistic regression to identify significant individual-, block-, and neighborhood-level covariates (neighborhood deprivation, segregation, population density).

RESULTS

Over half (55.9%, n=281) of fatal overdoses among PEH occurred in supportive housing or shelters, and 15.5% (n=78) occurred in public spaces (e.g., parks). Spatial analyses identified areas of significant concentrated fatal overdoses among PEH in Manhattan, the South Bronx, and Brooklyn. We identified several significant indicators of physical and social order and disorder associated with increased odds of experiencing homelessness at time of fatal overdose, including construction/renovation, graffiti, traffic calming features, and loitering.

CONCLUSION

Harm reduction services should be co-located in facilities that serve PEH and targeted to street blocks with indicators of physical and social disorder. While supportive housing is a crucial step in preventing fatal opioid overdoses among PEH, identifying neighborhoods for intervention services delivery and harm reduction outreach for PEH is necessary.

Comparing Projected Fatal Overdose Outcomes and Costs of Strategies to Expand Community-Based Distribution of Naloxone in Rhode Island

Importance

In 2021, the state of Rhode Island distributed 10 000 additional naloxone kits compared with the prior year through partnerships with community-based organizations.

Objective

To compare various strategies to increase naloxone distribution through community-based programs in Rhode Island to identify one most effective and efficient strategy in preventing opioid overdose deaths (OODs).

Design, Setting, and Participants

In this decision analytical model study conducted from January 2016 to December 2022, a spatial microsimulation model with an integrated decision tree was developed and calibrated to compare the outcomes of alternative strategies for distributing 10 000 additional naloxone kits annually among all individuals at risk for opioid overdose in Rhode Island.

Interventions

Distribution of 10 000 additional naloxone kits annually, focusing on people who inject drugs, people who use illicit opioids and stimulants, individuals at various levels of risk for opioid overdose, or people who misuse prescription opioids vs no additional kits (status quo). Two expanded distribution implementation approaches were considered: one consistent with the current spatial distribution patterns for each distribution program type (supply-based approach) and one consistent with the current spatial distribution of individuals in each of the risk groups, assuming that programs could direct the additional kits to new geographic areas if required (demand-based approach).

Main Outcomes and Measures

Witnessed OODs, cost per OOD averted (efficiency), geospatial health inequality measured by the Theil index, and between-group variance for OOD rates.

Results

A total of 63 131 simulated individuals were estimated to be at risk for opioid overdose in Rhode Island based on current population data. With the supply-based approach, prioritizing additional naloxone kits to people who use illicit drugs averted more witnessed OODs by an estimated mean of 18.9% (95% simulation interval [SI], 13.1%-30.7%) annually. Expanded naloxone distribution using the demand-based approach and focusing on people who inject drugs had the best outcomes across all scenarios, averting an estimated mean of 25.3% (95% SI, 13.1%-37.6%) of witnessed OODs annually, at the lowest mean incremental cost of $27 312 per OOD averted. Other strategies were associated with fewer OODs averted at higher costs but showed similar patterns of improved outcomes and lower unit costs if kits could be reallocated to areas with greater need. The demand-based approach reduced geospatial inequality in OOD rates in all scenarios compared with the supply-based approach and status quo.

Conclusions and Relevance

In this decision analytical model study, variations in the effectiveness, efficiency, and health inequality of the different naloxone distribution expansion strategies and approaches were identified. Future efforts should be prioritized for people at highest risk for overdose (those who inject drugs or use illicit drugs) and redirected toward areas with the greatest need. These findings may inform future naloxone distribution priority settings.

Prevalence and associates of non-fatal overdose among people who inject drugs in Saveh, Iran

Background

As a public health issue, non-fatal overdose (NFOD) is highly prevalent among people who inject drugs (PWID). This can lead to an elevated risk of future overdose, causing various harms including possible death. It is essential to improve knowledge concerning this problem and its associated risk factors to inform overdose prevention and assistance programs. The primary aim of the present study was to determine the prevalence of NFOD and associated risk factors among PWID in Saveh, Iran.

Methods

In the present cross-sectional study, 272 PWID living in Saveh, Iran were interviewed face-to-face using a structured survey. Data concerning socio-demographics, substance use, risky behaviors, and services utilization data were collected. The outcome variable (i.e., NFOD) was assessed by answering “Yes” to the question: “In the past three months, have you ever overdosed (at least once) by accident?”

Results

The prevalence of NFOD among PWID in the past three months was 54%. The characteristics and behaviors that were associated with an increased risk of experiencing NFOD in the past three months were being of older age (AOR = 5.2, p < 0.05), drug use initiation under the age of 22 years (AOR = 7.8, p < 0.05), being an alcohol user (AOR = 3.0, p < 0.05), and being a simultaneous multiple drug user (AOR = 5.8, p < 0.05). Also, more recent initiates to injecting (< 2 years) had an increased risk of experiencing a non-fatal overdose in the past three months. Findings also indicated that those who (i) attended a needle and syringe program (AOR: 0.3, p < 0.05), (ii) were visited by a general practitioner (AOR: 0.03, p < 0.05), and (iii) received a psychosocial intervention (AOR: 0.1, p < 0.05) were 0.3, 0.03 and 0.1 times less likely to report non-fatal overdosing than other participants, respectively.

Conclusions

The results indicate that intervention and prevention initiatives seeking to reduce NFOD among PWID should not only be focused on the primary drug used but also the use of alcohol and polysubstance use. Specific and tailored psychological interventions combined with pharmacotherapy may be highly beneficial for PWID who experience more severe types of substance use, including alcohol use disorders and/or polysubstance abuse.

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.

Ketamine plus Alcohol: What We Know and What We Can Expect about This

Drug abuse has become a public health concern. The misuse of ketamine, a psychedelic substance, has increased worldwide. In addition, the co-abuse with alcohol is frequently identified among misusers. Considering that ketamine and alcohol share several pharmacological targets, we hypothesize that the consumption of both psychoactive substances may synergically intensify the toxicological consequences, both under the effect of drugs available in body systems and during withdrawal. The aim of this review is to examine the toxicological mechanisms related to ketamine plus ethanol co-abuse, as well the consequences on cardiorespiratory, digestive, urinary, and central nervous systems. Furthermore, we provide a comprehensive discussion about the probable sites of shared molecular mechanisms that may elicit additional hazardous effects. Finally, we highlight the gaps of knowledge in this area, which deserves further research.

Factors associated with perceived decline in the quality of drugs during the COVID-19 pandemic: Evidence from community-recruited cohorts of people who use drugs in Vancouver, Canada

OBJECTIVES

Driven by an increasingly toxic drug supply, drug toxicity deaths in the United States and Canada have risen to unprecedented levels during the COVID-19 pandemic. This study aimed to characterize the prevalence of and the factors associated with a perceived decline in the quality of drugs during the COVID-19 pandemic among community-recruited cohorts of PWUD in Vancouver, Canada.

METHODS

Data collection took place between July and November 2020. In adherence with COVID-19 safety protocols, questionnaires were administered by interviewers through remote means (e.g., phone or videoconference). Using multivariable logistic regression, we characterized the prevalence of and factors associated with a perceived decline in drug quality during the start of the COVID-19 pandemic in Vancouver, Canada.

RESULTS

Of the 738 individuals included in this analysis, 272 (36.9%) reported that the quality of drugs declined during the COVID-19 pandemic. In multivariable analysis, perceived decline in the quality of drugs was significantly associated with: recent non-fatal overdose (adjusted odds ratio [AOR]=2.01, 95% Confidence Interval [CI]: 1.29-3.15), at least weekly injection drug use (AOR=1.94, 95% CI: 1.40-2.71), at least weekly crack use (AOR=1.61, 95%CI: 1.10-2.36), and at least weekly crystal methamphetamine use (AOR=1.46, 95%CI: 1.03-2.08).

DISCUSSION

Over a third of PWUD perceived that the quality of drugs declined during the COVID-19 pandemic and these individuals were significantly more likely to report experiencing a recent non-fatal overdose, engaging in frequent injection drug and stimulant use. Study findings indicate the need for interventions to address the toxic drug supply, including providing a regulated supply.

Health harms of non-medical prescription opioid use: A systematic review

ISSUES

Non-medical prescription opioid use (NMPOU) contributes substantially to the global burden of morbidity. However, no systematic assessment of the scientific literature on the associations between NMPOU and health outcomes has yet been undertaken.

APPROACH

We undertook a systematic review evaluating health outcomes related to NMPOU based on ICD-10 clinical domains. We searched 13 electronic databases for original research articles until 1 July 2021. We employed an adaptation of the Oxford Centre for Evidence-Based Medicine 'Levels of Evidence' scale to assess study quality.

KEY FINDINGS

Overall, 182 studies were included. The evidence base was largest on the association between NMPOU and mental and behavioural disorders; 71% (129) studies reported on these outcomes. Less evidence exists on the association of NMPOU with infectious disease outcomes (26; 14%), and on external causes of morbidity and mortality, with 13 (7%) studies assessing its association with intentional self-harm and 1 study assessing its association with assault (<1%).

IMPLICATIONS

A large body of evidence has identified associations between NMPOU and opioid use disorder as well as on fatal and non-fatal overdose. We found equivocal evidence on the association between NMPOU and the acquisition of HIV, hepatitis C and other infectious diseases. We identified weak evidence regarding the potential association between NMPOU and intentional self-harm, suicidal ideation and assault.

DISCUSSION AND CONCLUSIONS

Findings may inform the prevention of harms associated with NMPOU, although higher-quality research is needed to characterise the association between NMPOU and the full spectrum of physical and mental health disorders.

Intoxication related to substances use in patients presenting to Ain Shams University Poisoning Treatment Center, Cairo, Egypt (2015-2019)

INTRODUCTION

Illicit drug use may result in several emergencies. Hospital emergency data can help to detect new patterns of substance use and high-risk trends of drug use. This epidemiological study aimed to investigate the pattern and outcome of cases with substance use intoxication who presented to Ain Shams University Poisoning Treatment Centre, Cairo, Egypt.

METHODS

This retrospective study included all cases of acute intoxication due to use/misuse of substances who presented to the centre during the period (2015-2019).

RESULTS

The study included 11 281 cases; young adults (aged 20-40 years) represented the greatest proportion of cases (6519, 57.8%). Males were the predominant gender in all age groups (representing 79.2% of the cases). Tramadol was the most common substance of exposure in all age groups except for children and adolescents where cannabis was the most common one. There were 162 fatalities (1.4% of all cases) and opioids had the greatest case fatality rate.

DISCUSSION AND CONCLUSIONS

Tramadol was the most used drug that resulted in acute intoxication, followed by cannabis. A total of 43.6% of the cases of acute intoxications were due to recreational use/misuse of prescription drugs.

Jail and overdose: assessing the community impact of incarceration on overdose

BACKGROUND AND AIMS

Incarceration produces a specific public health threat for drug overdose, and correctional settings do not offer medication for opioid use disorder. This study examined the overall impact of jail incarceration on overdose, the specific hazard for those booked on a syringe-related charge and the proportion of all overdose decedents in the community who were in the jail prior to death.

DESIGN AND SETTING

A cohort study of fatal overdose outcomes among a sample of individuals booked into and released from jail between 1 January 2017 and 31 December 2019. Marion County, IN, USA.

PARTICIPANTS

All individuals released from one county jail between 1 January 2017 and 31 December 2017 and decedents who died within the county from an accidental fatal overdose between January 2017 and December 2019.

MEASUREMENTS AND FINDINGS

Using information on all jail booking events, including charge type, during a 5-year period (January 2015-December 2019), we looked at the hazard of accidental fatal overdose post-release, controlling for age, sex and race. Of all overdose deaths in the county, 21% (n = 237) had been in the county jail within 2 years prior to their death. Each prior booking increased the hazard of mortality by approximately 20% [hazard ratio (HR) = 1.21, 95% confidence interval (CI) = 1.15, 1.28], while the presence of a syringe charge at most recent booking prior to release more than tripled the hazard of mortality (HR = 3.55, 95% CI = 2.55, 4.93).

CONCLUSIONS

In Marion County, IN, USA, there appears to be an association between increased risk of fatal drug overdose and both syringe-related arrests and repeat jail bookings.

Multiple Victimizations and Overdose Among Women With a History of Illicit Drug Use

The experiences of violence and overdose are highly prevalent among women who use illicit drugs. This study sought to ascertain whether multiple victimizations during adulthood increase the frequency of women's overdose. The sample comprised 218 women recruited at Philadelphia harm reduction sites during 2016-2017. Victimization was assessed as exposure to 16 types of adulthood violence. Three measures were constructed for multiple victimizations: continuous and categorical polyvictimization, and predominant violence domain. Negative binomial regression estimated the incidence rate ratio (IRR) of lifetime overdoses from multiple victimizations. Lifetime history of opioid use (88.6%) and drug injection (79.5%) were common. Among overdose survivors (68.5%), the median of lifetime overdoses was 3. The majority of participants (58.7%) were victims of predominantly sexual violence, 26.1% experienced predominantly physical abuse/assault, and 3.7% were victims of predominantly verbal aggression/coercive control. Participants reported a mean of seven violence types; the higher-score category of polyvictimization (9-16 violence types) comprised 41.7% of the total sample. In multivariable models, one-unit increase in continuous polyvictimization was associated with 4% higher overdose rates (IRR: 1.04, 95% confidence interval [CI]: [1.00, 1.08]). Compared to women who were not victimized (11.5%), those in the higher-score category of polyvictimization (IRR: 2.01; 95% CI: [1.06, 3.80]) and exposed to predominantly sexual violence (IRR: 2.10, 95% CI: [1.13, 3.91]) were expected to have higher overdose rates. Polyvictimization and sexual violence amplified the risk of repeated overdose among drug-involved women. Female overdose survivors need to be screened for exposure to multiple forms of violence, especially sexual violence. Findings underscore the need to scale-up victimization support and overdose prevention services for disenfranchised women.

Social-Structural Predictors of Fentanyl Exposure among Street Involved Youth

ObjectiveThe emergence of synthetic fentanyl has been a main contributor to North America's rising overdose death rates. While increasing attention has been given to drug-related harm among youth, little is known about how social-structural conditions influence their risk of fentanyl exposure. Therefore, we evaluated potential relationships between social-structural conditions and fentanyl exposure among youth who use illicit drugs in Vancouver, BC. Methods: Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort study. The ARYS cohort involves street-involved youth, who use illicit substances in Vancouver, Canada. A multivariable logic regression analysis model was used to identify social factors associated with recent fentanyl exposure as determined through urine drug screening. Results: Overall, 423 participants were included in this analysis, with 380 (38.23%) testing positive for recent fentanyl exposure. In a multivariable relative risk analysis, living in Vancouver's Downtown Eastside in the last six months (RR = 1.16, 95% CI: 1.03-1.32) and daily heroin injection drug use (RR = 1.31, 95% CI: 1.15 - 1.50) were positively associated with fentanyl exposure. As a secondary measure, we found that within the encounters who denied using fentanyl (92.25% of total encounters), 321 (35.05%) still tested positive. Conclusions: We found that youth residing in Vancouver's Downtown Eastside was positively associated with being exposed to fentanyl. Our findings highlight the need to support youth in finding secure housing outside of Vancouver's drug use epicenter to reduce fentanyl exposure.

Prevalence and correlates of intentional substance use to reduce illicit opioid use in a Canadian setting

Background

While preliminary evidence has begun to document intentional use of one substance to reduce the use of another, the phenomenon of drug substitution among people who use illicit opioids remains understudied. Therefore, we sought to estimate the prevalence and correlates of intentional substance use to reduce illicit opioid use among persons who use drugs (PWUD).

Methods

We analysed data from three prospective cohorts of PWUD in Vancouver, Canada, using multivariable generalized estimating equations (GEE).

Results

Between June 2012 and June 2016, 1527 participants were recruited and contributed 4991 interviews. Of those, 336 (22%) illicit opioid-using participants self-reported substitution to reduce illicit opioid use at least once during study period contributing 467 (9.4%) interviews. Among those interviews, substances substituted for opioids were alcohol (15 participants, 3.2%), stimulants (235, 50.3%), cannabis (129, 27.6%), benzodiazepines (21, 4.5%), and others (20, 4.3%). In multivariable GEE model adjusted for socio-demographic factors, reporting substitution to reduce illicit opioid use was positively associated with greater likelihood of daily cannabis use (Adjusted Odds Ratio = 1.56, 95% Confidence Interval: 1.24-1.96].

Conclusions

While daily cannabis use was associated with reporting opioid substitution attempts, additional study is needed to examine potential of cannabis/cannabinoids to reduce illicit opioid use.

Increasing preference for fentanyl among a cohort of people who use opioids in Vancouver, Canada, 2017-2018

Background: Despite increasing prevalence of illicit fentanyl use in the US and Canada, preference for fentanyl over other illicit opioids has not been fully characterized. Therefore, we sought to describe changes in illicit opioid preferences over time among people who inject drugs (PWID). Methods: Data were obtained from two prospective cohort studies between 2017 and 2018. Trends in opioid preference over time were examined using bivariable generalized estimating equation (GEE) analysis. Multivariable models were used to identify factors associated with fentanyl preference. Results: Among 732 eligible participants, including 425 (58%) males, the prevalence of preference for fentanyl increased from 4.4% in 2017 to 6.6% in 2018 (Odds Ratio [OR] = 1.27, 95% Confidence Interval [CI]: 1.05-1.52). In a multivariable analysis, younger age (Adjusted Odds Ratio [AOR] = 0.94, 95% CI: 0.92-0.96) and daily crystal methamphetamine injection (AOR = 1.68, 95% CI: 1.01-2.78) were independently associated with preference for fentanyl. The most common reasons for preferring fentanyl included "better high than other opioids" (45%), and "lasts longer than heroin" (27%). Conclusions: The current study has demonstrated that preference for fentanyl has been increasing over time among our sample of PWID who use opioids. Further work is needed to clarify risk factors surrounding transitions to illicit fentanyl.

Harm Reduction Policy Support among Students at Two U.S. Universities

Background: The U.S. is undergoing an opioid overdose crisis. Harm reduction (HR) policies are associated with decreased overdose deaths and incidence of communicable diseases, yet legality of HR policies differs across U.S. jurisdictions. College student perceptions of HR policies are underexplored, even though their voting behavior has increased in recent years. We sought to compare their support of different HR policies and to explore relationships between demographic characteristics and support for HR policies. Methods: We collected cross-sectional, convenience sample survey data from undergraduate students at two large public universities, one in the Midwest and one in the Southeast, during Fall 2018/Spring 2019. We analyzed data using descriptive statistics and logistic regressions. Results: The final sample included 1,263 respondents. Good Samaritan laws (n = 833, 66%) and naloxone distribution (n = 476, 37.7%) were most commonly supported, while heroin maintenance treatment (n = 232, 18.4%) and heroin decriminalization (n = 208, 16.5%) were least supported. Democrat/liberal or less religious/spiritual respondents supported HR policies more than their Republican/conservative or religious/spiritual counterparts. Midwestern students were more likely to support syringe services programs. Conclusion: HR education initiatives could target religious and/or Republican/conservative students, as they have lower HR support. Among HR policies, Good Samaritan policies may be easiest to pass in college communities.

Prevalence of co-occurring mental illness and substance use disorder and association with overdose: a linked data cohort study among residents of British Columbia, Canada

AIMS

To estimate the treated prevalence of mental illness, substance use disorder (SUD) and dual diagnosis and the association between dual diagnosis and fatal and non-fatal overdose among residents of British Columbia (BC), Canada.

DESIGN

A retrospective cohort study using linked health, income assistance, corrections and death records.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

A total of 921 346 BC residents (455 549 males and 465 797 females) aged 10 years and older.

MEASUREMENTS

Hospital and primary-care administrative data were used to identify a history of mental illness only, SUD only, dual diagnosis or no history of SUD or mental illness (2010-14) and overdoses resulting in medical care (2015-17). We calculated crude incidence rates of non-fatal and fatal overdose by dual diagnosis history. Andersen-Gill and competing risks regression were used to examine the association between dual diagnosis and non-fatal and fatal overdose, respectively, adjusting for age, sex, comorbidities, incarceration history, social assistance, history of prescription opioid and benzodiazepine dispensing and region of residence.

FINDINGS

Of the 921 346 people in the cohort, 176 780 (19.2%), 6147 (0.7%) and 15 269 (1.7%) had a history of mental illness only, SUD only and dual diagnosis, respectively; 4696 (0.5%) people experienced 688 fatal and 6938 non-fatal overdoses. In multivariable analyses, mental illness only, SUD only and dual diagnosis were associated with increased rate of non-fatal [hazard ratio (HR) = 1.8, 95% confidence interval (CI) = 1.6-2.1; HR = 9.0, 95% CI = 7.0-11.5, HR = 8.7, 95% CI = 6.9-10.9, respectively] and fatal overdose (HR = 1.6, 95% CI = 1.3-2.0, HR = 4.3, 95% CI = 2.8-6.5, HR = 4.1, 95% CI = 2.8-6.0, respectively) compared with no history.

CONCLUSIONS

In a large sample of residents of British Columbia (Canada), approximately one in five people had sought care for a substance use disorder or mental illness in the past 5 years. The rate of overdose was elevated in people with a mental illness alone, higher again in people with a substance use disorder alone and highest in people with a dual diagnosis. The adjusted hazard rates were similar for people with substance use disorder only and people with a dual diagnosis.

Non-fatal opioid overdose, naloxone access, and naloxone training among people who recently used opioids or received opioid agonist treatment in Australia: The ETHOS Engage study

BACKGROUND

Overdose is a major cause of morbidity and mortality among people who use opioids. Naloxone can reverse opioid overdoses and can be distributed and administered with minimal training. People with experience of overdose are a key population to target for overdose prevention strategies. This study aims to understand if factors associated with recent non-fatal opioid overdose are the same as factors associated with naloxone access and naloxone training in people who recently used opioids or received opioid agonist treatment (OAT).

METHODS

ETHOS Engage is an observational study of people who inject drugs in Australia. Logistic regression models were used to estimate odds ratios for non-fatal opioid overdose, naloxone access and naloxone training.

RESULTS

Between May 2018-September 2019, 1280 participants who recently used opioids or received OAT were enrolled (62% aged >40 years; 35% female, 80% receiving OAT, 62% injected drugs in the preceding month). Recent opioid overdose (preceding 12 months) was reported by 7% of participants, lifetime naloxone access by 17%, and lifetime naloxone training by 14%. Compared to people receiving OAT with no additional opioid use, recent opioid, benzodiazepine (preceding six months), and hazardous alcohol use was associated with recent opioid overdose (aOR 3.91; 95%CI: 1.68-9.10) and lifetime naloxone access (aOR 2.12; 95%CI 1.29-3.48). Among 91 people who reported recent overdose, 65% had never received take-home naloxone or naloxone training.

CONCLUSIONS

Among people recently using opioids or receiving OAT, benzodiazepine and hazardous alcohol use is associated with non-fatal opioid overdose. Not all factors associated with non-fatal overdose correspond to factors associated with naloxone access. Naloxone access and training is low across all groups. Additional interventions are needed to scale up naloxone provision.

Drug type and risk behaviors associated with non-fatal overdose among people who use drugs: a systematic review and meta-analysis

The present study aimed to determine the association between drug type, risk behaviors and non-fatal overdose among people who use drugs (PWUD). We searched for studies in English published before February 1, 2021, on PubMed, Scopus, Cochrane, and Web of Science to identify primary studies on the factors associated with non-fatal overdose among PWUD. After reviewing for study duplicates, the full-text of selected articles were assessed for eligibility using Population, Intervention, Comparator, Outcomes (PICO) criteria. After a detailed assessment of over 13,845 articles, a total of 49 studies met the eligibility criteria. We found that non-injection opioid use, heroin injection, cocaine use, concurrent use of buprenorphine and benzodiazepines, benzodiazepine use, incarceration, injecting drugs, and duration of injecting were associated with greater odds of non-fatal overdose among PWUD. The findings of the current meta-analysis support the requirement to improve suitable harm reduction strategies for drug users, such as peer-based overdose management, and further focusing on the need to balance the current emphasis on enforcement-based responses to illegal drug use with health-related interventions.

Assisted injection provider practices and motivations in Los Angeles and San Francisco California 2016-18

BACKGROUND

Assisted injection is a high-risk and common practice among people who inject drugs (PWID) and occurs for diverse reasons according to qualitative research. To develop interventions for reducing assisted injection risks, it is important to understand the practices of PWID who provide injection assistance, including their motivations for providing assistance.

METHODS

Using follow-up data from an efficacy trial among PWID recruited in Los Angeles and San Francisco, CA (n=601), we present descriptive statistics on motivations for providing injection assistance and use multivariable logistic regression modelling to examine factors associated with these motivations.

RESULTS

PWID provided injection assistance most commonly to friends and acquaintances. A quarter provided assistance on a daily basis. The most common motivations for providing assistance were skill and injury prevention. PWID also provided assistance to stop pestering and for compensation in money or drugs. In separate models examining factors associated with the five main motivations, we found injury prevention to be associated with skill injecting others, neck injection, methamphetamine use, and recycling income. Pestering was associated with injury prevention, neck and hand injection, speedball use, and syringe selling. Skill was associated with injury prevention, neck and hand injection, being physically assaulted, and age. Providing assistance for money was associated with providing assistance for food or drugs, armpit injections, being female, and providing assistance more frequently. Providing assistance for drugs was associated with compensation in food or money, goofball injection, selling drugs, and panhandling.

CONCLUSION

Providing injection assistance is associated with injection needs of recipients and drug scene participation. We urgently need new interventions for reducing assisted injection risks. Since injection providers report being motivated by skill and to prevent injury, interventions such as training in safer injection techniques are likely to be met with enthusiasm.

Risk of non-fatal overdose and polysubstance use in a longitudinal study with people who inject drugs in Tijuana, Mexico

INTRODUCTION

Among people who inject drugs (PWID), polysubstance use has been associated with fatal and non-fatal overdose (NFOD). However, the risk of overdose due to the cumulative number of various recently used drug types remains unexplored. We estimated the risk of NFOD for different polysubstance use categories among PWID in Tijuana, Mexico.

METHODS

Data came from 661 participants followed for 2 years in Proyecto El Cuete-IV, an ongoing prospective cohort of PWID. A multivariable Cox model was used to assess the cumulative impact of polysubstance use on the time to NFOD. We used the Cochran-Armitage test to evaluate a dose-response relationship between number of polysubstance use categories and NFOD.

RESULTS

We observed 115 NFOD among 1029.2 person-years of follow-up (incidence rate: 11.2 per 100 person-years; 95% confidence interval [CI] 9.3-13.3). Relative to those who used one drug class, the adjusted hazard ratio of NFOD for individuals reporting using two drug classes was 1.11 (95% CI 0.69-1.79), three drug classes was 2.00 (95% CI 1.16-3.44) and for those reporting three compared to two was 1.79 (95% CI 1.09-2.97). A significant Cochran-Armitage trend test (P < 0.001) suggested a dose-response relationship.

DISCUSSION AND CONCLUSIONS

Polysubstance use was associated with increased risk of NFOD with a dose-response relationship over 2 years. We identified a subgroup of PWID at high risk of NFOD who reported concurrent use of opioids, stimulants and benzodiazepines. Prioritising tailored harm reduction and overdose prevention interventions for PWID who use multiple substances in Tijuana is needed.

Navigating post-eviction drug use amidst a changing drug supply: A spatially-oriented qualitative study of overlapping housing and overdose crises in Vancouver, Canada

BACKGROUND

North American cities are experiencing intersecting housing and overdose crises as illicit drug markets become marked by the proliferation of fentanyl and methamphetamine. Despite recent research documenting associations between evictions and drug-related risks and harms, including overdose, the mechanisms through which these occur remain poorly understood. This study to examines how evictions shape the drug use practices of people who use drugs in Vancouver's Downtown Eastside - a neighbourhood with an established drug scene - as the illicit drug supply changed.

METHODS

Qualitative interviews and geo-spatial data collection were conducted with 56 recently evicted PWUD. Data were analyzed by interfacing qualitative and geo-spatial data, and interpreted focusing on how structural vulnerability shaped spatial practices and drug-related risks post-eviction.

RESULTS

Findings demonstrate how post-eviction spatial practices and routines produced risk and harm as participants navigated the uncertainties of housing vulnerability and drug supply changes. Post-eviction disruptions complicated participants' ability to engage with trusted drug sellers. Changes to spatial patterns and access to private spaces rendered public drug use inevitable, though this was mitigated to some degree by harm reduction supports. Abrupt changes to drug use patterns occurred due to post-eviction disruptions and included instrumental uses of methamphetamine to increase alertness and navigate survival amidst severe hardship.

CONCLUSIONS

Findings demonstrate how post-eviction changes to routines and spatial patterns are framed by structural vulnerability and can exacerbate drug-related harms, particularly in the context of a changing drug supply. There is an urgent need for structural interventions and harm reduction responses to mitigate harms associated with evictions.

High prevalence of co-occurring substance use in individuals with opioid use disorder

OBJECTIVE

Funding to address the current opioid epidemic has focused on treatment of opioid use disorder (OUD); however, rates of other substance use disorders (SUDs) remain high and non-opioid related overdoses account for nearly 30% of overdoses. This study assesses the prevalence of co-occurring substance use in West Virginia (WV) to inform treatment strategies. The objective of this study was to assess the prevalence of, and demographic and clinical characteristics (including age, gender, hepatitis C virus (HCV) status) associated with, co-occurring substance use among patients with OUD in WV.

METHODS

This retrospective study utilized the West Virginia Clinical and Translation Science Institute Integrated Data Repository, comprised of Electronic Medical Record (EMR) data from West Virginia University Medicine. Deidentified data were extracted from inpatient psychiatric admissions and emergency department (ED) healthcare encounters between 2009 and 2018. Eligible patients were those with OUD who had a positive urine toxicology screen for opioids at the time of their initial encounter with the healthcare system. Extracted data included results of comprehensive urine toxicology testing during the study timeframe.

RESULTS

3,127 patients met the inclusion criteria of whom 72.8% had co-occurring substance use. Of those who were positive for opioids and at least one additional substance, benzodiazepines were the most common co-occurring substances (57.4% of patients yielded a positive urine toxicology screen for both substances), followed by cannabis (53.1%), cocaine (24.5%) and amphetamine (21.6%). Individuals who used co-occurring substances were younger than those who were positive for opioids alone (P < 0.001). There was a higher prevalence of individuals who used co-occurring substances that were HCV positive in comparison to those who used opioids alone (P < 0.001). There were limited gender differences noted between individuals who used co-occurring substances and those who used opioids alone. Among ED admissions who were positive for opioids, 264 were diagnosed with substance toxicity/overdose, 78.4% of whom had co-occurring substance use (benzodiazepines: 65.2%; cannabis: 44.4%; cocaine: 28.5%; amphetamine: 15.5%). Across the 10-year timespan, the greatest increase for the entire sample was in the rate of co-occurring amphetamine and opioid use (from 12.6% in 2014 to 47.8% in 2018).

CONCLUSIONS

These data demonstrate that the current substance use epidemic extends well beyond opioids, suggesting that comprehensive SUD prevention and treatment strategies are needed, especially for those substances which do not yet have any evidence-based and/or medication treatments available.

Deconstructing the 'cheque effect': short-term changes in injection drug use after receiving income assistance and associated factors

BACKGROUND AND AIMS

Disbursement of income assistance has been temporally associated with intensified drug use and related harms (coined the 'cheque effect'). However, relationships to injection drug use (IDU) remain understudied. We examined short-term 'cheque effects' and associated factors among people who inject drugs (PWID).

DESIGN

Cross-sectional analysis nested within a cohort study.

SETTING

Montreal, Quebec, Canada.

PARTICIPANTS

PWID receiving income assistance, with no employment income. A total of 613 PWID (median age 41, 83% male) contributed 3269 observations from 2011 to 2017.

MEASUREMENTS AND METHODS

At each cohort visit, an interviewer-administered questionnaire captured retrospective reports of injection-related behaviour during the 2-day periods (i) before and (ii) including/after receiving last month's income assistance payment (number of injections; drugs injected; any receptive syringe-sharing). The relative likelihood (odds) and magnitude (rate) of an increase in injection frequency ('cheque effect') were estimated in relation to social and behavioural factors using logistic and negative binomial regression in a covariate-adjusted two-part model.

FINDINGS

Prevalence of IDU and syringe-sharing were, respectively, 1.80 and 2.50 times higher in the days following versus preceding cheque receipt (P < 0.001). Among people with past-month IDU, most observations showed increased injection frequency (52%) or no change in injection frequency (44%). The likelihood of a 'cheque effect' was positively associated with cocaine injection [versus injection of other substances, odds ratio (OR) = 2.639, 95% confidence interval (CI) = 2.04-3.41], unstable housing (OR = 1.272, 95% CI = 1.03-1.57) and receiving opioid agonist therapy (OR =1.597, 95% CI = 1.27-2.00) during the same month. Magnitude of the 'cheque effect' was positively associated with cocaine injection [rate ratio (RR) = 1.795, 95% CI = 1.43-2.16], unstable housing (RR = 1.198, 95% CI = 1.02-1.38) and frequent injection (RR = 2.938, 95% CI = 2.43-3.44), but inversely associated with opioid agonist therapy (RR = 0.817, 95% CI = 0.68-0.95) and prescription opioid injection (RR = 0.794, 95% CI = 0.66-0.93).

CONCLUSION

Among people who inject drugs in Montreal, Canada, injection drug use and receptive syringe-sharing appear to be more prevalent in the 2 days after versus before receiving income assistance. The odds and rate of individual-level increases in injection frequency appear to be positively associated with cocaine injection (versus injection of other substances) and unstable housing.

Factors associated with health-related cannabis use intentions among a community sample of people who inject drugs in Los Angeles and San Francisco, CA 2016 to 2018

OBJECTIVE

Cannabis motivations have been studied extensively among patients of medicinal cannabis dispensaries, but less is known about motivations in community samples of opioid-using people who inject drugs. Our objective is to describe cannabis use motivations associated with self-treatment of physical pain, emotional issues, and as an opioid substitute.

METHODS

Data come from 6-month follow-up interviews with people who inject drugs who participated in a study on the efficacy of an injection initiation prevention intervention in Los Angeles and San Francisco, California from 2016-18. The analytic sample consists of 387 people who inject drugs who reported past-month cannabis use. We developed multivariable logistic regression models by reported cannabis use motivations: physical pain relief, emotional problems, and opioid substitute.

RESULTS

The most common cannabis use motivations reported by people who inject drugs was to "get high," relieve physical pain and emotional problems, and reduce opioid use. In separate multivariate models, using cannabis for physical pain relief was associated with higher odds of using cannabis as a substitute for opioids; cannabis for emotional problems was associated with being diagnosed with depression; and cannabis as a substitute for opioids was associated with non-prescribed, non-injection methadone use.

CONCLUSION

People who inject drugs reported using cannabis for health-related motivations. This motivation aligns with health needs and suggests the acceptability of cannabis use for health reasons in this population. Studies to determine the medical effectiveness of cannabis products for these common health and mental health needs among people who inject drugs are needed.

Migration Patterns from an Open Illicit Drug Scene and Emergency Department Visits among People Who Use Illicit Drugs in Vancouver, Canada

BACKGROUND

People who use illicit drugs (PWUD) experience various adverse health outcomes leading to increased healthcare service utilization. PWUD are also a highly mobile population which poses challenges to healthcare delivery. The objective of this study was to identify migration patterns from the Downtown Eastside (DTES), an urban illicit drug scene in Vancouver and to estimate the impact of different migration patterns on two outcomes: a) emergency department (ED) visits and b) ED visits resulting in inpatient admission among PWUD.

METHODS

Three prospective cohorts of PWUD in Vancouver were linked with regional ED data. We defined the optimal number of trajectory groups that best represented distinct patterns of migration from Vancouver's DTES using a latent class growth analysis. Then, generalized estimating equations were used to estimate the effect of migration patterns on the two ED outcomes.

RESULTS

Four distinct migration trajectory patterns were identified among the 1210 included participants: PWUD who consistently lived in the DTES, those who migrated out of DTES early, those who migrated out of DTES late, and those who frequently revisited the DTES. Participants who frequently revisited the DTES had higher odds of an ED visit (adjusted odds ratio = 1.62; 95% confidence interval: 1.28-2.06). There was no significant association between migration patterns and inpatient admission.

CONCLUSIONS

We found that PWUD who frequently revisited the DTES were more likely to have utilized the ED, suggesting that there may be a subgroup of PWUD who are at increased risk of experiencing negative health outcomes.Supplemental data for this article is available online at 10.1080/10826084.2021.1958849.

Polysubstance use and association with opioid use disorder treatment in the US Veterans Health Administration

AIMS

To understand the role of comorbid substance use disorders (SUDs), or polysubstance use, in the treatment of opioid use disorder (OUD), this study compared patients with OUD only to those with additional SUDs and examined association with OUD treatment receipt.

DESIGN, SETTING AND PARTICIPANTS

Retrospective national cohort study of Veterans diagnosed with OUD (n = 65 741) receiving care from the US Veterans Health Administration (VHA) in fiscal year (FY) 2017.

MEASUREMENTS

Patient characteristics were compared among those diagnosed with OUD only versus those with one other SUD (OUD + 1 SUD) and with multiple SUDs (OUD + ≥ 2 SUDs). The study examined the relationship between comorbid SUDs and receipt of buprenorphine, methadone and SUD outpatient treatment during 1-year follow-up, adjusting for patient demographic characteristics and clinical conditions.

FINDINGS

Among the 65 741 Veterans with OUD in FY 2017, 41.2% had OUD only, 22.9% had OUD + 1 SUD and 35.9% had OUD + ≥ 2 SUDs. Common comorbid SUDs included alcohol use disorder (41.3%), cocaine/stimulant use disorder (30.0%) and cannabis use disorder (22.4%). Adjusting for patient characteristics, patients with OUD + 1 SUD [adjusted odds ratio (aOR) = 0.87, 95% confidence interval (CI) = 0.82-0.93] and patients with OUD +≥ 2 SUDs (aOR = 0.65, 95% CI = 0.61-0.69) had lower odds of receiving buprenorphine compared with OUD only patients. There were also lower odds of receiving methadone for patients with OUD + 1 SUD (aOR = 0.91, 95% CI = 0.86-0.97)and for those with OUD + ≥2 SUDs (aOR = 0.79, 95% CI = 0.74-0.84). Patients with OUD + 1 SUD (aOR = 1.85, 95% CI = 1.77-1.93) and patients with OUD + ≥2 SUDs (aOR = 3.25, 95% CI = 3.103.41) were much more likely to have a SUD clinic visit.

CONCLUSIONS

The majority of Veterans in the US Veterans Health Administration diagnosed with opioid use disorder appeared to have at least one comorbid substance use disorder and many have multiple substance use disorders. Despite the higher likelihood of a substance use disorder clinic visit, having a non-opioid substance use disorder is associated with lower likelihood of buprenorphine treatment, suggesting the importance of addressing polysubstance use within efforts to expand treatment for opioid use disorder.