Peer Support Workers Study

Investigators will evaluate the Peer Support intervention using two analytical approaches:

1. Primary Analysis (Intention-to-Treat): Peer Available Shift Patients who presented to the emergency department (ED) with substance use-related complaints during shifts when a Peer support worker was scheduled to be available, according to an a priori randomized schedule. Patients may or may not have directly interacted with a Peer during their ED visit. All eligible patients will be analyzed according to their randomized shift assignment, regardless of whether a direct Peer-patient interaction occurred.
2. Secondary Analysis: Interacted With Peer Patients who presented to the ED with substance use-related concerns and directly interacted with a Peer support worker during their ED visit. Peer activities may have included harm reduction support, provision of naloxone and sterile drug use supplies, linkage to substance use treatment, and connections to follow-up care and community resources.

During intervention shifts, Peer support workers were scheduled to be available in the emergency department to provide support to patients with substance use-related concerns. Peer support workers offered services tailored to individual patients' needs, including referrals to clinical and social support services (e.g., social work, addictions specialists, Indigenous patient navigators, and community-based addiction services), provision of resources (e.g., blankets, food, naloxone kits, sterile drug use supplies, and information brochures), emotional support, and communication support between patients and healthcare providers regarding patients' conditions and ED care. The primary analysis will evaluate the effect of randomized Peer availability using an intention-to-treat approach. The secondary analysis will evaluate outcomes associated with actual Peer-patient interactions by comparing patients who received Peer support with comparable patients who did not.

Investigators will define the comparison group using two approaches:

1. Primary Analysis (Intention-to-Treat): No Peer Available Shift Patients presenting to the ED with substance use-related complaints during shifts randomized to no Peer availability.
2. Secondary Analysis: Did Not Interact With Peer Patients presenting with similar substance use-related complaints who did not directly interact with a Peer. Investigators will use propensity score weighting to improve comparability with patients who received Peer support. The model will include relevant covariates (e.g., age, sex, area-level deprivation, prior substance use-related ED visits and hospitalizations, and prescriptions for substance dependence medications recorded in PharmaNet during the previous 12 months).

Investigators will measure LBTC among ED patients with substance use-related complaints (e.g., substance withdrawal, misuse/intoxication, overdose, and localized swelling/redness).

Investigators will evaluate LBTC using two approaches:

1. Primary Analysis (Intention-to-Treat): Peer vs. No Peer Shifts Investigators will classify eligible ED visits based on the randomized Peer schedule. For each shift, investigators will calculate the percentage of eligible visits resulting in LBTC. Linear regression will be used to compare LBTC percentages between Peer and No Peer shifts, regardless of actual Peer interaction.
2. Secondary Analysis: Peer Interaction vs. No Peer Interaction Investigators will use propensity score weighting to improve comparability between patients who interacted with a Peer and those who did not. Mixed-effects logistic regression will be used to compare LBTC probabilities between groups, accounting for clustering by shift and adjusting for relevant covariates.

Assessed by examining the distribution of scheduled Peer shifts across each day of the week over the 48-week randomized schedule period. The schedule was developed in collaboration with human resources and ED operational leadership and approved as meeting hospital employee policy. The randomization approach used block-based scheduling with built-in constraints (e.g., mandatory weekends off). This outcome evaluates whether the resulting schedule achieved a balanced weekday/weekend distribution.

Unit of Measure: Number and percentage of Peer shifts scheduled per day of the week

Secondary outcomes will include receipt of naloxone kits, opioid agonist therapy doses, and withdrawal treatments during the ED visit. Investigators will compare counts of these outcomes between intervention (Peer) and control (no Peer) groups using multivariable count regression. Investigators will assess clustering of outcomes by shift and adjust for the same covariates included in the primary analysis.

Exploratory outcomes will include ED visits, hospitalizations, drug poisoning, and mortality within 30 days following the index ED visit. Investigators will analyze counts of these events using multivariable count regression, with the log-transformed length of follow-up included as an offset term where applicable, and will conduct time-to-event analyses using Cox regression. Investigators will assess clustering of outcomes by shift and adjust for the same covariates included in the primary analysis.

Investigators will obtain records of security-related events occurring during ED visits over the study period from the ED security event database. Investigators will assess whether Peer availability was associated with differences in the frequency and type of security-related events, including escalation events and incidents requiring security involvement.

Indigenous patient perspectives on the Peer program will be collected through surveys, culturally grounded storytelling and sharing circles. Sessions will be guided by open-ended questions to explore perceived safety, support, and emotional impact of Peer involvement in the emergency department. Transcripts will be analyzed using Indigenous-informed thematic analysis to identify key insights and priorities for culturally safe care.

Unit of Measure: Themes and narratives identified through qualitative analysis

Acceptability of the Peer program among healthcare providers will be evaluated using semi-structured focus groups conducted periodically post-implementation. Discussions will explore perceived value, observed patient impact, integration into ED workflows, challenges, and suggestions for improvement. Audio recordings will be transcribed and analyzed using thematic content analysis to identify recurring patterns and representative quotes.

Unit of Measure: Thematic categories identified through qualitative analysis

Perspectives of people with lived and living experience (PWLLE) on the Peer program will be evaluated using semi-structured focus groups. Discussions will explore participants' perceptions of the value and accessibility of Peer support, experiences of substance use-related care in the ED, perceived impacts of the Peer program, barriers and gaps in care, and suggestions for improving Peer support and program delivery. Audio recordings will be transcribed and analyzed using thematic content analysis to identify recurring themes and representative quotes. Unit of Measure: Thematic categories identified through qualitative analysis

Acceptability and implementation of the Peer program will be assessed through periodic surveys administered to Peers, patients accessing Peer services, members of the ED buprenorphine/naloxone team, and multidisciplinary healthcare providers. Surveys will assess experiences with the Peer program, including perceived value, respect, ease of communication, clarity of information, comfort, confidentiality, teamwork, integration into ED workflows, and perceived facilitators and barriers to implementation.