Approach to Unhoused Patients Presenting to the Emergency Department with a History of Opioid Use Disorder

In Knowledge Translation by Richard ChengLeave a Comment

Editor’s Note: This is part 2 of a 2-part series on homelessness. Check out Part I about the Ottawa Inner City Health Initiative.

‘Ken’ is a 47-year-old unhoused man presenting to the Emergency Department (ED) with severe opioid withdrawal symptoms. After taking his history, you learn that he has been unhoused for the past 2 years and using non-prescribed fentanyl for the past 8 months. His last dose was 28 hours ago. You administer suboxone to help manage his withdrawal. Following the suboxone administration, Ken has been stable in the ED for the past 2 hours and you are now looking to discharge him safely.


In 2021, almost 8000 opioid-related deaths occurred in Canada with over 75% of deaths involving fentanyl. ​1​ Sixty percent of Opioid Use Disorder (OUD) hospitalizations occur among unhoused individuals.​2​ The convergence of being unhoused and OUDs presents a multifaceted and complex challenge when it comes to discharge due to a lack of primary care, housing, and addictions therapy.

This article aims to explore the complexities surrounding unhoused individuals presenting with OUDs in the ED, focusing on evidence-based considerations for their safe and effective discharge.

Motivational Interviewing

Motivational interviewing is a patient-centered approach focused on an individual’s values and autonomy to guide conversations regarding changing behaviors that are unhealthy or suboptimal, such as use of opioids. Studies have previously shown even a brief motivational interviewing session in the ED can significantly decrease rates of non-medical opioid use and overdose risk behaviors among patients in the pre-contemplation phase of quitting opioid use.​3​

Motivational interviewing follows a four-step process​3​ including:

  1. Engaging the patient by setting the agenda and providing information in a respectful manner
  2. Focusing on a specific aspect of their addiction that can result in actionable change
  3. Evoking patients’ perspectives and
  4. Planning change by addressing facilitators and barriers.

Throughout the motivational interviewing, a collaborative relationship can be established with the OARS mnemonic​4​:

  • Open-ended questions to explore patient’s perspectives
  • Affirmations and validation of patient’s thoughts, ideas, actions
  • Reflections to demonstrate active-listening and understanding of the patient
  • Summaries that extend past the reflection to develop direction and momentum in conversation.

Offer Opioid Agonist Treatment (OAT)

Unhoused individuals are more likely to seek support for detoxification and opioid-related care in the ED. ​5​ As such, starting OAT for consenting unhoused individuals is an important consideration in the ED. Buprenorphine-naloxone (Suboxone), serves as a first-line medication for the treatment of opioid withdrawal. Ensuring proper patient education regarding OAT is essential in its adoption as a treatment. Ultimately, prior studies have shown OATs can significantly reduce all-cause and opioid-overdose mortality when compared with no-intervention. In a systematic review, when compared with no-intervention, OAT was able to reduce the risk of all-cause mortality in those with OUDs by more than half.​6​ Furthermore, ED-initiated buprenorphine significantly increased engagement in addiction treatment and decreased use of inpatient addiction services compared to referral or brief interventions alone.​7​ This is especially important among unhoused patients where use of inpatient addiction services may be inaccessible.

Providing Naloxone

Naloxone is an opioid antagonist that can serve as a life-saving intervention for individuals with an opioid overdose. The ED serves as a key point-of-care for opioid overdose education and naloxone distribution, especially for unhoused individuals. However, a prior systematic review  showed low uptake of the practice. Cited barriers include the burden of workflow and increased time required to train hospital staff.​8​  Despite this, naloxone distribution is essential with one study reporting that 16% of patients provided take-home naloxone kits in the ED went on to use it to rescue someone with an opioid overdose.​8​

Addressing Social and Mental Health Needs

The social needs of those who are unhoused adds an extra layer of complexity when discharging unhoused people with an OUD. The Canadian Medical Association Journal has provided a clinical practice guideline identifying several evidenced-based needs of the unhoused.​9​

1. Connecting unhoused individuals to housing interventions ​9​

Connecting unhoused individuals to a local housing coordinator or case manager for access to permanent supportive housing and/or shelters is an essential first step to their OUD management. Supportive housing and shelters take in unhoused individuals, regardless of their SUD status and has been shown to greatly improve OAT retention by 2.5-fold compared to their unhoused counterparts at three-years follow up.

2. Comorbid mental-health management ​9​

It is essential for unhoused people with an OUD to have access to local community mental health programs, psychiatric services, and long-term case management whenever available. Having a comorbid mental disorder along with an OUD raises an individual’s odds of all-cause mortality by 1.4 times. Furthermore, estimated ED visits and rates of hospitalization were 2.25 and 1.67 times higher, respectively.

3. Arrange follow-up with OAT counseling services ​9​

OAT counseling services at a local consumption and treatment services center has been shown to increase retention of OAT from 62% to 74% (NNT = 8). These services are essential as a point-of-care for unhoused people to access a continuous supply of buprenorphine-naloxone, seek mental health services, receive harm-reduction education, and social support services (i.e., housing and income assistance). 

Case Conclusion

Through motivational interviewing Ken seemed interested in the idea of quitting. You share your concerns over continued opioid use and present OAT as an option in addition to other supportive social services. Ken agrees. After providing him with buprenorphine-naloxone and a take-home naloxone kit, you also involve the ED social worker to further discuss connecting Ken with supportive housing services, a local community mental health program, and OAT counseling services to provide him longer-term buprenorphine-naloxone. You thank Ken for his openness to discussing treatment for his OUD and Ken thanks you for the support you provide him.

This post was copyedited by Saad Razzaq


  1. 1.
    Fischer B. The continuous opioid death crisis in Canada: changing characteristics and implications for path options forward. The Lancet Regional Health – Americas. Published online March 2023:100437. doi:10.1016/j.lana.2023.100437
  2. 2.
    Substance-related poisonings and homelessness in Canada: a descriptive analysis of hospitalization data. Government of Canada. Published September 14, 2021. Accessed November 26, 2023. https://www.canada.ca/en/health-canada/services/opioids/hospitalizations-substance-related-poisonings-homelessness.html
  3. 3.
    Bohnert ASB, Bonar EE, Cunningham R, et al. A pilot randomized clinical trial of an intervention to reduce overdose risk behaviors among emergency department patients at risk for prescription opioid overdose. Drug and Alcohol Dependence. Published online June 2016:40-47. doi:10.1016/j.drugalcdep.2016.03.018
  4. 4.
    Smedslund G, Berg RC, Hammerstrøm KT, et al. Motivational interviewing for substance abuse. Cochrane Database of Systematic Reviews. Published online May 11, 2011. doi:10.1002/14651858.cd008063.pub2
  5. 5.
    McLaughlin MF, Li R, Carrero ND, Bain PA, Chatterjee A. Opioid use disorder treatment for people experiencing homelessness: A scoping review. Drug and Alcohol Dependence. Published online July 2021:108717. doi:10.1016/j.drugalcdep.2021.108717
  6. 6.
    Santo T, Clark B, Hickman M, et al. Association of Opioid Agonist Treatment With All-Cause Mortality and Specific Causes of Death Among People With Opioid Dependence: A Systematic Review and Meta-analysis. JAMA Psychiatry. 2021;78(9):979-993. doi:10.1001/jamapsychiatry.2021.0976
  7. 7.
    D’Onofrio G, Chawarski M, O’Connor P, et al. Emergency Department-Initiated Buprenorphine for Opioid Dependence with Continuation in Primary Care: Outcomes During and After Intervention. J Gen Intern Med. 2017;32(6):660-666. doi:10.1007/s11606-017-3993-2
  8. 8.
    Gunn A, Smothers Z, Schramm-Sapyta N, Freiermuth C, MacEachern M, Muzyk A. The Emergency Department as an Opportunity for Naloxone Distribution. West J Emerg Med. 2018;19(6):1036-1042. doi:10.5811/westjem.2018.8.38829
  9. 9.
    Pottie K, Kendall C, Aubry T, et al. Clinical guideline for homeless and vulnerably housed people, and people with lived homelessness experience. CMAJ. 2020;192(10):E240-E254. doi:10.1503/cmaj.190777

Reviewing with the staff

The intertwining crises of homelessness and opioid use disorder (OUD) pose a pressing challenge for emergency departments (EDs) across Canada. This article highlights the multifaceted obstacles ED professionals encounter when discharging such patients and emphasizes evidence-based interventions like motivational interviewing, opioid agonist treatment (OAT), naloxone distribution, and a more comprehensive approach to social and mental health needs. The article is not just a testament to the changing landscape of care but a clear call for EDs to embrace an evolved, patient-centric approach to unhoused patients with OUDs. Ensuring a safe discharge is no longer just about treating the immediate symptoms; it\'s about weaving a holistic safety net for a vulnerable population that\'s often overlooked.

Dr. Susan Bartels
Dr. Susan Bartels, MD, MPH, FRCPC, is a Clinician-Scientist and Canada Research Chair in Humanitarian Health Equity at Queen’s University. She practices emergency medicine at the Kingston Health Sciences Center and has a focus on health equity and the social determinants of health. She does not have any conflicts of interest to declare. Email: [email protected]