Barriers and facilitators to the implementation of rapid HIV testing in Canadian Emergency Departments: a mixed methods study.

OBJECTIVES: 1 in 7 Canadians with Human Immunodeficiency Virus (HIV) do not know their status. Patients at increased risk of HIV routinely access the emergency department (ED), yet few are tested, representing a missed opportunity for diagnosis and linkage-to-care. Rapid HIV testing provides reliable results within the same ED encounter but is not routinely implemented. The objective of this study was to identify barriers and facilitators to rapid HIV testing in Ontario EDs. METHODS: We employed a mixed-methods, convergent, parallel design study including online surveys and semi-structured interviews of physicians, nurses, and allied health across four hospitals in Toronto and Thunder Bay, Ontario. Data were analyzed in equal priority using descriptive statistics for quantitative data and thematic analysis for qualitative data guided by the Theoretical Domains framework and Capability, Opportunity, Motivation Behaviour change model. RESULTS: Among 187 survey respondents, 150 (80%) felt implementing rapid HIV testing would be helpful in the ED. Facilitators included availability of resources to link patients to care after testing (71%), testing early in patient encounters (41%), and having dedicated staff with lived experience support testing (34%). Motivation to offer testing included opportunities to support an underserved population (66%). Challenges to implementation included limited time during ED patient encounters (51%) and a lack of knowledge around HIV testing (42%) including stigma. Interview themes confirmed education, and integration of people with lived experience being essential to provide rapid HIV testing and linkage-to-care in the ED. CONCLUSIONS: Implementation of rapid HIV testing in the ED is perceived to be important irrespective of practice location or profession. Intrinsic motivations to support underserved populations and providing linkage-to-care are novel insights to facilitate testing in the ED. Streamlined implementation, including clear testing guidelines and improved access to follow-up care, is felt to be necessary for implementation.

ABSTRAIT: OBJECTIFS: 1 Canadien sur 7 atteint du virus de l'immunodéficience humaine (VIH) ne connaît pas son statut. Les patients présentant un risque accru de contracter le VIH ont régulièrement accès au service des urgences (SU), mais peu d'entre eux sont testés, ce qui représente une occasion manquée de diagnostic et de lien avec les soins. Le dépistage rapide du VIH fournit des résultats fiables dans la même situation d'urgence, mais n'est pas systématiquement mis en œuvre. L'objectif de cette étude était d'identifier les obstacles et les facilitateurs au dépistage rapide du VIH dans les urgences de l'Ontario. MéTHODES: Nous avons utilisé une étude de conception mixte, convergente et parallèle, y compris des sondages en ligne et des entrevues semi-structurées auprès de médecins, d'infirmières et d'auxiliaires de la santé dans quatre hôpitaux de Toronto et de Thunder Bay, en Ontario. Les données ont été analysées en priorité égale à l'aide de statistiques descriptives pour les données quantitatives et d'analyses thématiques pour les données qualitatives guidées par le cadre des domaines théoriques et le modèle de changement de capacité, d'opportunité et de motivation. RéSULTATS: Parmi 187 répondants au sondage, 150 (80 %) étaient d'avis que la mise en œuvre d'un dépistage rapide du VIH serait utile à l'urgence. Les facilitateurs comprenaient la disponibilité de ressources pour lier les patients aux soins après le test (71 %), le dépistage précoce lors des rencontres avec les patients (41 %) et la présence d'un personnel dévoué avec des tests de soutien de l'expérience vécue (34 %). La motivation à offrir des tests comprenait des occasions de soutenir une population mal desservie (66 %). Les difficultés de mise en œuvre comprenaient un temps limité pendant les rencontres avec les patients aux urgences (51 %) et un manque de connaissances sur le dépistage du VIH (42 %), y compris la stigmatisation. Les thèmes des entrevues ont confirmé que l'éducation et l'intégration des personnes ayant une expérience vécue sont essentielles pour fournir un dépistage rapide du VIH et un lien avec les soins aux urgences. CONCLUSIONS: La mise en œuvre du dépistage rapide du VIH aux urgences est perçue comme importante, quel que soit le lieu de pratique ou la profession. Les motivations intrinsèques à soutenir les populations mal desservies et à fournir un lien avec les soins sont de nouvelles idées pour faciliter les tests à l'urgence. Une mise en œuvre simplifiée, y compris des lignes directrices claires sur les tests et un meilleur accès aux soins de suivi, est jugée nécessaire pour la mise en œuvre.

Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE-4): Alcohol use disorder and cannabinoid hyperemesis syndrome management in the emergency department.

The fourth Society for Academic Emergency Medicine (SAEM) Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE-4) is on the topic of the emergency department (ED) management of nonopioid use disorders and focuses on alcohol withdrawal syndrome (AWS), alcohol use disorder (AUD), and cannabinoid hyperemesis syndrome (CHS). The SAEM GRACE-4 Writing Team, composed of emergency physicians and experts in addiction medicine and patients with lived experience, applied the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach to assess the certainty of evidence and strength of recommendations regarding six priority questions for adult ED patients with AWS, AUD, and CHS. The SAEM GRACE-4 Writing Team reached the following recommendations: (1) in adult ED patients (over the age of 18) with moderate to severe AWS who are being admitted to hospital, we suggest using phenobarbital in addition to benzodiazepines compared to using benzodiazepines alone [low to very low certainty of evidence]; (2) in adult ED patients (over the age of 18) with AUD who desire alcohol cessation, we suggest a prescription for one anticraving medication [very low certainty of evidence]; (2a) in adult ED patients (over the age of 18) with AUD, we suggest naltrexone (compared to no prescription) to prevent return to heavy drinking [low certainty of evidence]; (2b) in adult ED patients (over the age of 18) with AUD and contraindications to naltrexone, we suggest acamprosate (compared to no prescription) to prevent return to heavy drinking and/or to reduce heavy drinking [low certainty of evidence]; (2c) in adult ED patients (over the age of 18) with AUD, we suggest gabapentin (compared to no prescription) for the management of AUD to reduce heavy drinking days and improve alcohol withdrawal symptoms [very low certainty of evidence]; (3a) in adult ED patients (over the age of 18) presenting to the ED with CHS we suggest the use of haloperidol or droperidol (in addition to usual care/serotonin antagonists, e.g., ondansetron) to help with symptom management [very low certainty of evidence]; and (3b) in adult ED patients (over the age of 18) presenting to the ED with CHS, we also suggest offering the use of topical capsaicin (in addition to usual care/serotonin antagonists, e.g., ondansetron) to help with symptom management [very low certainty of evidence].

Factors associated with frequent buprenorphine / naloxone initiation in a national survey of Canadian emergency physicians.

OBJECTIVE: To identify individual and site-related factors associated with frequent emergency department (ED) buprenorphine/naloxone (BUP) initiation. BUP initiation, an effective opioid use disorder (OUD) intervention, varies widely across Canadian EDs. METHODS: We surveyed emergency physicians in 6 Canadian provinces from 2018 to 2019 using bilingual paper and web-based questionnaires. Survey domains included BUP-related practice, demographics, attitudes toward BUP, and site characteristics. We defined frequent BUP initiation (the primary outcome) as at least once per month, high OUD prevalence as at least one OUD patient per shift, and high OUD resources as at least 3 out of the following 5 resources: BUP initiation pathways, BUP in ED, peer navigators, accessible addiction specialists, and accessible follow-up clinics. We excluded responses from sites with <50% participation (to minimize non-responder bias) and those missing the primary outcome. We used univariate analysis to identify associations between frequent BUP initiation and factors of interest, stratifying by OUD prevalence. RESULTS: We excluded 3 responses for missing BUP initiation frequency and 9 for low response rate at one ED. Of the remaining 649 respondents from 34 EDs, 374 (58%) practiced in metropolitan areas, 384 (59%) reported high OUD prevalence, 312 (48%) had high OUD resources, and 161 (25%) initiated BUP frequently. Age, gender, board certification and years in practice were not associated with frequent BUP initiation. Site-specific factors were associated with frequent BUP initiation (high OUD resources [OR 6.91], high OUD prevalence [OR 4.45], and metropolitan location [OR 2.39],) as were individual attitudinal factors (willingness, confidence, and responsibility to initiate BUP.) Similar associations persisted in the high OUD prevalence subgroup. CONCLUSIONS: Individual attitudinal and site-specific factors were associated with frequent BUP initiation. Training to increase physician confidence and increasing OUD resources could increase BUP initiation and benefit ED patients with OUD.

Substance use care innovations during COVID-19: barriers and facilitators to the provision of safer supply at a toronto COVID-19 isolation and recovery site.

BACKGROUND: Early in the COVID-19 pandemic, there was an urgent need to establish isolation spaces for people experiencing homelessness who were exposed to or had COVID-19. In response, community agencies and the City of Toronto opened COVID-19 isolation and recovery sites (CIRS) in March 2020. We sought to examine the provision of comprehensive substance use services offered to clients on-site to facilitate isolation, particularly the uptake of safer supply prescribing (prescription of pharmaceutical opioids and/or stimulants) as part of a spectrum of comprehensive harm reduction and addiction treatment interventions. METHODS: We conducted in-depth, semi-structured interviews with 25 clients and 25 staff (including peer, harm reduction, nursing and medical team members) from the CIRS in April-July 2021. Iterative and thematic analytic methods were used to identify key themes that emerged in the interview discussions. RESULTS: At the time of implementation of the CIRS, the provision of a safer supply of opioids and stimulants was a novel and somewhat controversial practice. Prescribed safer supply was integrated to address the high risk of overdose among clients needing to isolate due to COVID-19. The impact of responding to on-site overdoses and presence of harm reduction and peer teams helped clinical staff overcome hesitation to prescribing safer supply. Site-specific clinical guidance and substance use specialist consults were crucial tools in building capacity to provide safer supply. Staff members had varied perspectives on what constitutes 'evidence-based' practice in a rapidly changing, crisis situation. CONCLUSION: The urgency involved in intervening during a crisis enabled the adoption of prescribed safer supply, meeting the needs of people who use substances and assisting them to complete isolation periods, while also expanding what constitutes acceptable goals in the care of people who use drugs to include harm reduction approaches.

Considerations for the design of overdose education and naloxone distribution interventions: results of a multi-stakeholder workshop.

INTRODUCTION: Opioid overdose epidemic is a public health crisis that is impacting communities around the world. Overdose education and naloxone distribution programs equip and train lay people to respond in the event of an overdose. We aimed to understand factors to consider for the design of naloxone distribution programs in point-of-care settings from the point of view of community stakeholders. METHODS: We hosted a multi-stakeholder co-design workshop to elicit suggestions for a naloxone distribution program. We recruited people with lived experience of opioid overdose, community representatives, and other stakeholders from family practice, emergency medicine, addictions medicine, and public health to participate in a full-day facilitated co-design discussion wherein large and small group discussions were audio-recorded, transcribed and analysed using thematic approaches. RESULTS: A total of twenty-four participants participated in the multi-stakeholder workshop from five stakeholder groups including geographic and setting diversity. Collaborative dialogue and shared storytelling revealed seven considerations for the design of naloxone distribution programs specific to training needs and the provision of naloxone, these are: recognizing overdose, how much naloxone, impact of stigma, legal risk of responding, position as conventional first aid, friends and family as responders, support to call 911. CONCLUSION: To create an naloxone distribution program in emergency departments, family practice and substance use treatment services, stigma is a central design consideration for training and naloxone kits. Design choices that reference the iconography, type, and form of materials associated with first aid have the potential to satisfy the need to de-stigmatize overdose response.

Design details for overdose education and take-home naloxone kits: Codesign with family medicine, emergency department, addictions medicine and community.

INTRODUCTION: Overdose education and naloxone distribution (OEND) programmes equip and train people who are likely to witness an opioid overdose to respond with effective first aid interventions. Despite OEND expansion across North America, overdose rates are increasing, raising questions about how to improve OEND programmes. We conducted an iterative series of codesign stakeholder workshops to develop a prototype for take-home naloxone (THN)-kit (i.e., two doses of intranasal naloxone and training on how to administer it). METHODS: We recruited people who use opioids, frontline healthcare providers and public health representatives to participate in codesign workshops covering questions related to THN-kit prototypes, training on how to use it, and implementation, including refinement of design artefacts using personas and journey maps. Completed over 9 months, the workshops were audio-recorded and transcribed with visible results of the workshops (i.e., sticky notes, sketches) archived. We used thematic analyses of these materials to identify design requirements for THN-kits and training. RESULTS: We facilitated 13 codesign workshops to identify and address gaps in existing opioid overdose education training and THN-kits and emphasize timely response and stigma in future THN-kit design. Using an iterative process, we created 15 prototypes, 3 candidate prototypes and a final prototype THN-kit from the synthesis of the codesign workshops. CONCLUSION: The final prototype is available for a variety of implementation and evaluation processes. The THN-kit offers an integrated solution combining ultra-brief training animation and physical packaging of nasal naloxone to be distributed in family practice clinics, emergency departments, addiction medicine clinics and community settings. PATIENT OR PUBLIC CONTRIBUTION: The codesign process was deliberately structured to involve community members (the public), with multiple opportunities for public contribution. In addition, patient/public participation was a principle for the management and structuring of the research team.

Resuscitation simulation among people who are likely to witness opioid overdose: Experiences from the SOONER Trial.

The opioid crisis is a growing public health emergency and increasing resources are being directed towards overdose education. Simulation has emerged as a novel strategy for training overdose response, yet little is known about training non-clinicians in bystander resuscitation. Understanding the perspectives of individuals who are likely to experience or witness opioid overdose is critical to ensure that emergency response is effective. The Surviving Opioid Overdose with Naloxone Education and Resuscitation (SOONER) study evaluates the effectiveness of a novel naloxone education and distribution tool among people who are non-clinicians and likely to witness opioid overdose. Participants' resuscitation skills are evaluated using a realistic overdose simulation as the primary outcome of the trial. The purpose of our study is to describe the experience of participants with the simulation process in the SOONER study. We employed a semi-structured debriefing interview and a follow up qualitative interview to understand the experience of participants with simulation. A qualitative content analysis was performed using data from 21 participants who participated in the SOONER study. Our qualitative analysis identified 5 themes and 17 subthemes which described the experience of participants within the simulation process. These themes included realism, valuing practical experience, improving self-efficacy, gaining new perspective and bidirectional learning. Our analysis found that simulation was a positive and empowering experience for participants in the SOONER trial, most of whom are marginalized in society. Our study supports the notion that expanding simulation-based education to non-clinicians may offer an acceptable and effective way of supplementing current opioid overdose education strategies. Increasing the accessibility of simulation-based education may represent a paradigm shift whereby simulation is transformed from a primarily academic practice into a patient-based community resource.

Phenobarbital for the management of severe acute alcohol withdrawal (the PHENOMANAL trial): a pilot randomized controlled trial.

BACKGROUND: Benzodiazepines are considered first-line treatment for patients experiencing severe acute alcohol withdrawal syndrome (sAAWS). Although several medications have been evaluated as potential adjuvant treatments for sAAWS, barbiturates show particular promise. OBJECTIVE: In the PHENOMANAL trial, we will assess the feasibility of conducting an allocation-concealed, quadruple-blinded, randomized controlled trial (RCT) comparing symptom-triggered benzodiazepine therapy with either a single dose of adjuvant intravenous (IV) phenobarbital (7.5 mg/kg of ideal body weight) or a single dose of matching IV placebo for patients with sAAWS. METHODS: We will recruit adult patients from the Emergency Department, Intensive Care Unit, or hospital wards with a Clinical Institute of Withdrawal - Adult revised (CIWA-Ar) score of 16 or more after receipt of at least 60 mg of diazepam or equivalent within 16 h of diagnosis of sAAWS, and an anticipated need for hospitalization. We will randomize participants (n=39) in a 2:1 manner to treatment and placebo groups, respectively. The primary objective of the PHENOMANAL pilot trial will be to demonstrate our ability to recruit the desired population over the trial period. As secondary objectives, we will evaluate clinician compliance with the treatment protocols, assess crossover rates from the placebo arm to the treatment arm, and obtain preliminary estimates of treatment effect. All trial participants will be followed for 7 days or until hospital discharge. RELEVANCE: The PHENOMANAL trial is novel in investigating a new treatment for a common and understudied condition, repurposing an existing medication for a novel indication, and addressing an important evidence gap. Through conduct of the multidisciplinary pilot trial, we aim to advance methodology in acute care research through the use of a hybrid consent model and inform the design of a large-scale trial. TRIAL REGISTRATION: ClinicalTrials.gov Registration NCT03586089 ; first registered July 13, 2018.

Facilitators of and barriers to buprenorphine initiation for people with opioid use disorder in the emergency department: protocol for a scoping review.

INTRODUCTION: Buprenorphine-naloxone is recommended as a first-line agent for the treatment of opioid use disorder. Although initiation of buprenorphine in the emergency department (ED) is evidence based, barriers to implementation persist. A comprehensive review and critical analysis of both facilitators of and barriers to buprenorphine initiation in ED has yet to be published. Our objectives are (1) to map the implementation of buprenorphine induction pathway literature and synthesise what we know about buprenorphine pathways in EDs and (2) to identify gaps in this literature with respect to barriers and facilitators of implementation. METHODS AND ANALYSIS: We will conduct a scoping review to comprehensively search the literature, map the evidence and identify gaps in knowledge. The review will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols Extension for Scoping Reviews and guidance from the Joanna Briggs Institution for conduct of scoping reviews. We will search Medline, APA, PsycINFO, CINAHL, Embase and IBSS from 1995 to present and the search will be restricted to English and French language publications. Citations will be screened in Covidence by two trained reviewers. Discrepancies will be mediated by consensus. Data will be synthesised using a hybrid, inductive-deductive approach, informed by the Consolidated Framework for Implementation Research as well as critical theory to guide further interpretation. ETHICS AND DISSEMINATION: This review does not require ethics approval. A group of primary knowledge users, including clinicians and people with lived experience, will be involved in the dissemination of findings including publication in peer-reviewed journals. Results will inform future research, current quality improvement efforts in affiliated hospitals, and aide the creation of a more robust ED response to the escalating overdose crisis.

A cross-sectional survey on buprenorphine-naloxone practice and attitudes in 22 Canadian emergency physician groups: a cross-sectional survey.

BACKGROUND: Buprenorphine-naloxone (BUP) initiation in emergency departments improves follow-up and survival among patients with opioid use disorder. We aimed to assess self-reported BUP-related practices and attitudes among emergency physicians. METHODS: We designed a cross-sectional physician survey by adapting a validated questionnaire on opioid harm reduction practices, attitudes and barriers. We recruited physician leads from 6 Canadian provinces to administer surveys to the staff physicians in their emergency department groups between December 2018 and November 2019. We included academic and community non-locum emergency department staff physicians. We excluded responses from emergency department groups with response rates less than 50% to minimize nonresponse bias. Primary (BUP prescribing practices) and secondary (willingness and attitudes) outcomes were analyzed using descriptive statistics. RESULTS: After excluding 1 group for low response (9/26 physicians), 652 of 798 (81.7%) physicians responded from 22 groups serving 34 emergency departments. Among respondents, 64.1% (95% confidence interval [CI] 60.4%-67.8%, emergency department group range 7.1%-100.0%) had prescribed BUP at least once in their career, 38.4% had prescribed it for home initiation and 24.8% prescribed it at least once a month. Overall, 68.9% (95% CI 65.3%-72.4%, emergency department group range 24.1%-97.6%) were willing to administer BUP, 64.2% felt it was a major responsibility and 37.1% felt they understood people who use drugs. Respondents most frequently rated lack of adequate training (58.2%) and lack of time (55.2%) as very important barriers to BUP initiation. INTERPRETATION: Two-thirds of the emergency physicians surveyed prescribed BUP, although only one-quarter did so regularly and one-third prescribed it for home initiation; wide variation between emergency department groups existed. Strategies to increase BUP initiation must address physicians' lack of time and training for BUP initiation and improve their understanding of people who use drugs.

Corrigendum to "Mixed methods feasibility study for the surviving opioid overdose with naloxone education and resuscitation (SOONER) trial" [Resuscitation Plus 6 (2021) 100131].

[This corrects the article DOI: 10.1016/j.resplu.2021.100131.].

Mixed methods feasibility study for the surviving opioid overdose with naloxone education and resuscitation (SOONER) trial.

AIM: We plan to conduct a randomised clinical trial among people likely to witness opioid overdose to compare the educational effectiveness of point-of-care naloxone distribution with best-available care, by observing participants' resuscitation skills in a simulated overdose. This mixed methods feasibility study aims to assess the effectiveness of recruitment and retention strategies and acceptability of study procedures. METHODS: We implemented candidate-driven recruitment strategies with verbal consent and destigmatizing study materials in a family practice, emergency department, and addictions service. People ≥16 years of age who are likely to witness overdose were randomized to point-of-care naloxone distribution or referral to an existing program. We evaluated participant skills as a responder to a simulated overdose 3-14 days post-recruitment. Retention strategies included flexible scheduling, reminders, cash compensation and refreshments. The primary outcome was recruitment and retention feasibility, defined as the ability to recruit 28 eligible participants in 28 days, with <50% attrition at the outcome simulation. Acceptability of study procedures and motivations for participation were assessed in a semi-structured interview. RESULTS: We enrolled 30 participants over 24 days, and retained 21 participants (70%, 95%CI 56.7-100). The most common motivation for participation was a desire to serve the community or loved ones in distress. Participants reported that study procedures were acceptable and that the outcome simulation provided a supportive and affirming environment. CONCLUSION: The planned trial is ready for implementation. Recruitment and retention is feasible and study processes are acceptable for people who are likely to witness overdose. (Registration: NCT03821649).

CAEP Position Statement: Emergency department management of people with opioid use disorder.

Deaths due to opioid overdose have reached unprecedented levels in Canada; over 12,800 opioid-related deaths occurred between January 2016 and March 2019, and overdose death rates increased by approximately 50% from 2016 to 2018.1 In 2016, Health Canada declared the opioid epidemic a national public health crisis,2 and life expectancy increases have halted in Canada for the first time in decades.3 Children are not exempt from this crisis, and the Chief Public Health Officer of Canada has recently prioritized the prevention of problematic substance use among Canadian youth.4.

Protocol for a mixed-methods feasibility study for the surviving opioid overdose with naloxone education and resuscitation (SOONER) randomised control trial.

INTRODUCTION: The surviving opioid overdose with naloxone education and resuscitation (SOONER) project uses co-design and trial methods to develop and evaluate a point-of-care overdose education and naloxone distribution (OEND) tool. We plan to conduct a randomised controlled trial to assess the effectiveness of our OEND tool in comparison with best available standard of care by observing participants' performance as a responder to a simulated overdose. Recruiting and retaining people at risk of or likely to witness opioid overdose raises scientific, logistical and bioethical challenges. A feasibility study is needed to establish the effectiveness of recruitment and retention strategies and acceptability of study procedures prior to launching the full trial. METHODS AND ANALYSIS: Strategies to enhance recruitment include candidate-driven recruitment, verbal informed consent, and attractive, destigmatising materials. Adults at risk of or likely to witness opioid overdose will be recruited through an urban emergency department, inpatient and ambulatory addiction medicine service, and outpatient family practice settings. Participants randomised to the intervention arm will receive our OEND intervention; those in the control arm will be referred to existing OEND programme. Retention procedures include participant reminders, flexible scheduling, cash and comfort compensation, and strategies to maintain a consistent relationship between individual study staff and participants. Within 2 weeks following recruitment, participants will engage as a responder to a manikin-simulated overdose, and complete overdose knowledge and attitudes questionnaires. The primary outcome is recruitment and retention feasibility, defined as the recruitment of 28 participants within 28 days of recruitment and <50% attrition at the overdose simulation. Staff and participant feedback will also be collected and considered. ETHICS AND DISSEMINATION: The study has been reviewed by ethics boards at St. Michael's Hospital, Toronto Public Health and the University of Toronto. Dissemination will occur through peer-reviewed publication and presentations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov registry (NCT03821649).

Out-of-hospital cardiac arrest survival in drug-related versus cardiac causes in Ontario: A retrospective cohort study.

BACKGROUND: Drug overdose causes approximately 183,000 deaths worldwide annually and 50,000 deaths in Canada and the United States combined. Drug-related deaths are concentrated among young people, leading to a substantial burden of disease and loss of potential life years. Understanding the epidemiology, patterns of care, and prognosis of drug-related prehospital emergencies may lead to improved outcomes. METHODS: We conducted a retrospective cohort study of out-of-hospital cardiac arrests with drug-related and presumed cardiac causes between 2007 and 2013 using the Toronto Regional RescuNet Epistry database. The primary outcome was survival to hospital discharge. We computed standardized case fatality rates, and odds ratios of survival to hospital discharge for cardiac arrests with drug-related versus presumed cardiac causes, adjusting for confounders using logistic regression. RESULTS: The analysis involved 21,497 cardiac arrests, including 378 (1.8%) drug-related and 21,119 (98.2%) presumed cardiac. Compared with the presumed cardiac group, drug-related arrest patients were younger and less likely to receive bystander resuscitation, have initial shockable cardiac rhythms, or be transported to hospital. There were no significant differences in emergency medical service response times, return of spontaneous circulation, or survival to discharge. Standardized case fatality rates confirmed that these effects were not due to age or sex differences. Adjusting for known predictors of survival, drug-related cardiac arrest was associated with increased odds of survival to hospital discharge (OR1.44, 95%CI 1.15-1.81). INTERPRETATION: In out-of-hospital cardiac arrest, patients with drug-related causes are less likely than those with presumed cardiac causes to receive bystander resuscitation or have an initial shockable rhythm, but are more likely to survive after accounting for predictors of survival. The demographics and outcomes among drug-related cardiac arrest patients offers unique opportunities for prehospital intervention.