Evan Wood's research while affiliated with University of British Columbia - Vancouver and other places

Publications (723)

Article
Background: To evaluate how an international one-year intensive research training program for addiction medicine physicians contributed to subsequent research involvement and productivity. Methods: We prospectively compared addiction medicine physician fellows admitted to a one-year training program with non-admitted controls, using baseline questi...
Article
Background Substance use management in hospitals can be challenging. In response, a Canadian hospital opened an overdose prevention site (OPS) where community members and hospital inpatients can inject pre-obtained illicit drugs under supervision. This study aims to: (1) describe program utilization patterns; (2) characterize OPS visits; and (3) ev...
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Objective: Extensive exposure to prescription-type opioids has resulted in major harm worldwide, calling for better-adapted approaches to opioid agonist therapy. The authors aimed to determine whether flexible take-home buprenorphine/naloxone is as effective as supervised methadone in reducing opioid use in prescription-type opioid consumers with...
Article
Background and aims: Fentanyl is primarily responsible for the current phase of the overdose epidemic in North America. Despite the benefits of treatment with medications for opioid use disorder (MOUD), there are limited data on the association between fentanyl, MOUD type and treatment engagement. The objectives of this analysis were to measure th...
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Background Drug checking is a harm reduction intervention aiming to reduce substance use-related risks by improving drug user knowledge of the composition of unregulated drugs. With increasing fears of fentanyl adulteration in unregulated drugs, this study sought to examine whether the expected type of drug checked (stimulant vs. opioid) was associ...
Article
Objective: To examine the prevalence and correlation of self-reported inability to access community primary care clinics among people who inject drugs (PWID). Design: Self-report questionnaire data. Setting: Vancouver, BC. Participants: Data were derived from 3 prospective cohort studies of PWID between 2013 and 2016. Main outcome measures:...
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Background Violent victimization is common among people who use illegal drugs (PWUD) and is a source of significant health-related harm. However, little attention has been paid to how antecedent childhood trauma among PWUD may contribute to the risk of victimization in adulthood. Objective This study sought to examine the relationship between chil...
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Background Although oral opioid agonist therapies (OATs), buprenorphine and methadone, are effective first-line treatments, OAT remains largely underutilized due to low retention rates and wide variation across programs. This rapid review therefore sought to summarize the retention rates reported by randomized controlled trials (RCTs) and controlle...
Article
Background Little is known about the relationship between opioid agonist therapy (OAT) and fentanyl use, specifically. This study aimed to estimate the association between current use of different forms of OAT, including methadone, buprenorphine/naloxone (BUP/NX), slow release oral morphine (SROM), or injectable opioid agonist treatment (iOAT), and...
Article
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 st...
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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 pers...
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Background There is concern that cannabis use negatively affects vulnerable groups such as youth; however, the relationship between cannabis use and health care utilization has not been well characterized in this population. We longitudinally evaluated the association between daily cannabis use and hospitalization among a prospective cohort of stre...
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North America has been contending with an unregulated street drug supply in which opioids are often adulterated with illicitly manufactured fentanyl. The unpredictability of composition may result in an increased risk of overdose due to unexpected elevated concentrations of the high-potency drug. Using data from a community-based drug checking proj...
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Background The synchronised monthly disbursement of income assistance, whereby all recipients are paid on the same day, has been associated with increases in illicit drug use and serious associated harms. This phenomenon is often referred to as the cheque effect. Because payment variability can affect consumption patterns, this study aimed to asses...
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Background While exposure to traumatic events and subsequent post-traumatic stress disorder (PTSD) are common among people who use drugs (PWUD), little is known about gender-based differences associated with PTSD in this population. We explore gender-based differences in factors associated with a probable PTSD diagnosis in a cohort of PWUD from Van...
Article
Objectives: Gaps in addiction medicine training are a reason for poor substance use care in North America. Hospital addiction medicine consult services (AMCS) provide critical medical services, including screening and treatment of substance use disorders. Although these programs often feature an educational component for medical learners, the impa...
Article
Background With the emergence of unregulated fentanyl, people who use unregulated opioids are increasingly relying on appearance in an effort to ascertain the presence of fentanyl and level of drug potency. However, the utility of visual inspection to identify drug composition in the fentanyl era has not been assessed. Methods: We assessed client e...
Article
Introduction: Illicitly manufactured fentanyl continues to fuel the opioid overdose crisis throughout the USA and Canada. However, little is known about factors associated with knowingly or unknowingly using fentanyl. Therefore, we sought to identify the prevalence and correlates of suspected/known and unknown exposure to fentanyl (excluding the p...
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Introduction Retention in opioid agonist therapy consistently has been linked with improved outcomes among people with opioid use disorder. However, less is known about the links between patterns of engagement in opioid agonist therapy over the long term and overdose risk. This study assesses the association of opioid agonist therapy retention traj...
Preprint
Full-text available
Background: Drug checking is a harm reduction intervention aiming to reduce substance use-related risks by improving drug user knowledge of the composition of unregulated drugs. With increasing fears of fentanyl adulteration in unregulated drugs, this study sought to examine whether the expected type of drug checked (stimulant vs. opioid) was assoc...
Article
Background and Aims To improve evidence‐based addiction care in acute care settings, many hospitals across North America are developing an inpatient addiction medicine consult service (AMCS). St. Paul’s Hospital in Vancouver, Canada houses a large interdisciplinary AMCS. This study aimed to: (1) describe the current model of clinical care and its e...
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Background The United States and Canada are amidst an opioid overdose crisis, with the Canadian province of British Columbia (BC) among the hardest hit. In response, drug checking services (DCS) have been introduced in this setting as a novel pilot harm reduction intervention though little is known about usage rates. Therefore, we sought to identif...
Article
Background People who require help injecting illicit drugs experience elevated rates of a range of health-related harms, including overdose and acquisition of blood-borne pathogens. In response, some supervised injection services (SIS) in Canada have begun to permit clients to be physically injected by fellow clients or staff members. However, litt...
Article
Background The ongoing opioid overdose crisis is driven largely by exposure to illicitly-manufactured fentanyl. Preliminary observational and experimental research suggests that cannabis could potentially play a role in reducing use of prescription opioids among individuals with chronic pain. However, there is limited data on the effects of cannabi...
Article
Background The opioid overdose crisis underscores the need for health services among people who use drugs (PWUD) with concurrent pain. Aims Investigating the effect of pain on barriers to accessing health services among PWUD. Design Prospective cohort study. Settings A setting of universal access to no-cost medical care in Vancouver, Canada from...
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Aim: Given that co-occurring pain is prevalent among people who use drugs (PWUD), we sought to explore the effect of pain severity on accessing addiction treatment. Methods: Data were derived from two prospective cohort studies of PWUD in Vancouver, Canada from June 2014 to May 2016. Multivariable generalized linear mixed-effects multiple regres...
Article
Background: Opioid agonist therapy (OAT) models are generally provided without consideration of how pre-treatment characteristics may be associated with outcome. Therefore, we aimed to first characterize longitudinal trajectories of opioid use before initiating OAT. Then we explored the impact of OAT on opioid use across these pre-treatment trajec...
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Introduction: Despite a recent meta-analysis including 31 randomised controlled trials comparing methadone and buprenorphine for the treatment of opioid use disorder, important knowledge gaps remain regarding the long-term effectiveness of different treatment modalities across individuals, including rigorously collected data on retention rates and...
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ABSTRACT: Many British Columbians have become addicted to opioids as a result of unsafe opioid prescribing and the illicit opioid market. Although prescription opioid use disorder is associated with substantial morbidity and mortality, physicians currently have no way of identifying patients who can safely be prescribed long-term opioid therapy for...
Article
Background The United States and Canada are in the midst of an overdose epidemic, fueled by illicitly manufactured fentanyl. While marked differences in vulnerability to drug-related harm between men and women who use drugs is well characterized, the extent to which gender differences manifest in the present overdose crisis remains understudied. We...
Article
Background Pain can return temporarily to old injury sites during opioid withdrawal. The prevalence and impact of opioid withdrawal-associated injury site pain (WISP) in various groups is unknown. Methods Using data from observational cohorts, we estimated the prevalence and correlates of WISP among opioid-using people who inject drugs (PWID). Bet...
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Introduction Methamphetamine use is increasing in North America and is associated with numerous negative health effects and social harms. As drug‐related harms are often gendered, this study sought to examine the differential impacts of gender on the trends, risk factors and health implications of crystal methamphetamine use among a Canadian cohort...
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Aims Stimulant use disorder contributes to a substantial worldwide burden of disease, although evidence-based treatment options are limited. This systematic review of reviews aims to: (i) synthesize the available evidence on both psychosocial and pharmacological interventions for the treatment of stimulant use disorder; (ii) identify the most effec...
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We comment on developments in and impacts of medical opioid control and availability in the province of British Columbia (Canada). Population-level dispensing of (strong) prescription opioids doubled in 2005–2011, yet subsequently declined by half 2011–2018 following implementation of various opioid control measures. Notwithstanding this inversion,...
Article
Objectives Point-of-care drug checking services, wherein individuals can check the content and purity of their drugs, have emerged as a public health intervention to address the fentanyl crisis; however, there have been no rigorous evaluations of the technologies against reference standard laboratory techniques. Methods Two point-of-care technolog...
Article
Objectives Drug checking services aim to provide people who use drugs with information on the content and purity of their substances as a harm reduction intervention. The objective of this study was to determine the relationship between injecting alone and use of drug checking services in Vancouver, Canada. Methods Data were derived from three pro...
Article
Background and Aims: Little is known about how the expansion of opioid agonist therapy (OAT) and emergence of fentanyl in the illicit drug supply in North America has influenced non-fatal opioid overdose (NFOD) risk. Therefore, we sought to identify patterns of substance use and addiction treatment engagement (i.e., OAT, other inpatient or outpatie...
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Background: Substance use disorders represent a significant social and economic burden globally. Accurate diagnosis and treatment by early career professionals in addiction medicine (ECPAM) falls short, in part, due to a lack of training programmes targeting this career stage. Prior research has highlighted the need to assess the specific training...
Article
Background: Supervised injection facilities (SIFs) have been established in many settings, in part to reduce risks associated with injecting in public, including exposure to violence. However, the relationship between SIF use and experiencing violence has not yet been thoroughly evaluated. We sought to longitudinally examine the gender-specific rel...
Article
Background Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT. Methods Data for this st...
Article
Background North America is facing an unprecedented public health crisis of opioid-related morbidity and mortality, increasingly as a result of the introduction of illicitly manufactured fentanyl into the street drug market. Although the treatment of opioid use disorder (OUD) is a key element in the response to the opioid overdose epidemic, current...
Article
Background: Long-term engagement in opioid agonist therapy (OAT) has been consistently associated with reduced risk for morbidity and mortality in people with opioid use disorder (OUD). However, the dynamic nature of engagement/disengagement in OUD care for over time is poorly captured by traditional metrics. We characterized long-term longitudina...
Article
Background: Since 2013, fentanyl-contaminated drugs have been driving North America’s opioid-overdose epidemic. Drug checking, which enables people who use illicit drugs (PWUD) to test and receive feedback regarding the contents of their drugs, is being considered as a potential tool to address the toxic drug supply. While some PWUD witness overdos...
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Background: North America is in the midst of an opioid overdose epidemic. Although take-home naloxone and other measures have been an effective strategy to reduce overdoses, many events are unwitnessed and mortality remains high amongst those using drugs alone. While wearable devices that can detect and alert others of an overdose are being develo...
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Background People who inject drugs (PWID) experience elevated rates of premature mortality. Although previous studies have demonstrated the role of supervised injection facilities (SIFs) in reducing various harms associated with injection drug use, including accidental overdose death, the possible impact of SIF use on all-cause mortality is unknown...
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Background Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management. However, there is a lack of research using individual-level data to explore this question. We aimed to investigate the long...
Article
Introduction and aims: Drug checking is a harm reduction intervention increasingly used in the context of the opioid overdose epidemic. The aim of the study was to determine the limit of detection for fentanyl of two point-of-care drug checking technologies. Design and methods: Samples tested at point-of-care using Bruker Fourier transform infra...
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Background: The current opioid overdose epidemic affecting communities across North America is increasingly driven by illicitly manufactured fentanyl and its related analogues. A variety of public health interventions have been implemented and scaled up, including opioid agonist treatments (OAT). While these treatments are successful for many indiv...
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Background Post-traumatic stress disorder sharply increases the risk of depression and suicide. Individuals living with post-traumatic stress disorder frequently use cannabis to treat associated symptoms. We sought to investigate whether cannabis use modifies the association between post-traumatic stress disorder and experiencing a major depressive...
Article
The evidence for the management of noncancer pain among adults with acute and chronic pain conditions has evolved rapidly in recent years. Earlier recommendations and approaches resulted in more routine use of opioid analgesics.¹ As a result, it has been estimated that almost 40% of US civilian, noninstitutionalized adults used prescription opioids...
Article
Objectives: Drug checking is a harm reduction intervention that allows for identification of drug composition. The objective of the study was to assess drug market components and concordance between expected substance reported by clients and results from point-of-care drug checking at music festivals and events in British Columbia. Methods: From...
Article
Objectives: Opioid agonist therapy is the cornerstone of treatment of opioid use disorder. In Canada, buprenorphine/naloxone has recently been adopted as the first line agonist therapy given its comparable effectiveness to methadone and superior safety profile. This study examines factors associated with willingness to take buprenorphine/naloxone...
Article
Objective: North America is in the midst of a growing drug overdose crisis. While prescription opioid misuse and synthetic opioids such as fentanyl have been implicated in the overdose crisis, less attention has been given to the role that posttraumatic stress disorder (PTSD) may play in this crisis. As such, this study sought to examine the relat...
Article
Background: Emerging evidence suggests that non-medical prescription opioid (NMPO) use may be a risk factor for initiating heroin use; however, pathways from PO to heroin use among youth remain underexplored. We sought to examine the association between NMPO use and heroin initiation. Methods: Between September 2005 and June 2017 data were deriv...
Article
Issues: Canada recently introduced a public health-based regulatory framework for non-medical cannabis. This review sought to identify a comprehensive set of indicators to evaluate the public health and safety impact of cannabis regulation in Canada, and to explore the ways in which these indicators may be expected to change in the era of legal no...
Article
Background and aims: Many people who use drugs (PWUD) are coerced into receiving treatment. This study aimed to assess changes in substance use and related outcomes before versus after treatment in people coerced into treatment, voluntarily attending treatment or not attending treatment. Design: Data from three linked prospective cohort studies...
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Background and aims: Injection drug use patterns are known to change over time, although such long-term changes have not been well described. We sought to characterize longitudinal trajectories of injection drug use and identify associated factors. Design: Data were derived from the Vancouver Injection Drug Users Study and AIDS Care Cohort to ev...
Article
Background: The illicit selling and use of cannabis is prevalent among marginalized people who use illicit drugs (PWUD). Given that participation in illicit drug markets has been previously associated with a range of health and social harms, we sought to examine the predictors of selling cannabis among PWUD in Vancouver, Canada, a setting with a d...
Article
Objectives: In recent years, North America has witnessed a spike in the number of overdoses (OD) and OD-related deaths. The aim of this study was to assess spatial correlates of OD risk in Vancouver, Canada. Methods: Data utilized for this study was from three open and ongoing prospective cohorts of people who use drugs (PWUDs) in Vancouver, Can...
Article
Objectives: In North America, the illicit drug supply is increasingly contaminated by illicitly manufactured fentanyl. We sought to assess the level and source of fentanyl risk knowledge, defined as knowledge of the overdose risks associated with fentanyl, and characterize the prevalence and correlates of perceived risk of personally having a fent...
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Importance Although prescription opioid use disorder is associated with substantial harms, strategies to identify patients with pain among whom prescription opioids can be safely prescribed have not been systematically reviewed. Objective To review the evidence examining factors associated with opioid addiction and screening tools for identifying...
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Throughout the world, Indigenous populations experience a disproportionate burden of HIV infection. Maximally-assisted therapy (MAT) is an interdisciplinary care intervention that includes ART dispensation to support individuals with a history of addiction and homelessness. This study sought to longitudinally evaluate the relationship between engag...
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Objective To assess the efficacy of slow release oral morphine (SROM) as a treatment for opioid use disorder (OUD). Design Systematic review and meta-analysis of randomised controlled trials (RCTs). Data sources Three electronic databases were searched through 1 May 2018: the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE. We...
Article
Introduction and Aims While much research has sought to identify the factors associated with initiation and cessation of various forms of drug use among vulnerable youth, little is known about relapse into drug use in this population. We sought to characterise relapse into stimulant and opioid use among street‐involved youth in Vancouver, Canada....
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BACKGROUND: Opioid agonist therapy (OAT) is a first-line treatment for opioid use disorder (OUD); however, the efficacy and role of urine drug screening (UDS) in OAT has received little research attention. Prior evidence suggests that UDS frequency reflects philosophy and practice context rather than differences in patient characteristics or clinic...
Article
Background: Hospital-based clinical addiction medicine training can improve knowledge of clinical care for substance-using populations. However, application of structured, self-assessment tools to evaluate differences in knowledge gained by learners who participate in such training has not yet been addressed. Methods: Participants (n = 142) of a...
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Purpose of Review While the epidemiology of North America’s opioid crisis has been well understood, a need exists to evaluate the potential for its expansion to other international settings. Thus, a comprehensive summary of the factors that have contributed to North America’s opioid crisis, their impact on global opioid markets, and relevance in ot...
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Background: Methamphetamine use is common among some populations of gay, bisexual and other men who have sex with men (gbMSM). This study reviewed the status of research on the efficacy of interventions that address harms among gbMSM who use methamphetamine. Methods: We searched MEDLINE, PsycINFO, CINAHL, Embase, Cochrane Central Register of Con...