Canadian Anaphylaxis Network- Predicting Recurrence After Emergency Presentation for Allergic REaction (CAN-PREPARE)

BACKGROUND: Anaphylaxis is the most severe form of allergy that rapidly affects multiple body systems and can be deadly. The highest incidence of anaphylaxis is in children and adolescents. In Canada, approximately every 10 minutes there is an Emergency Department (ED) visit for food allergy, and up to 80% of anaphylactic reactions in children are triggered by food. The ambiguity in how physicians manage anaphylaxis adds a huge burden to health care and further contributes to ED crowding. Current Canadian and international treatment guidelines universally recommend that all patients present to the ED for a prolonged period (6-24 hours) of in-hospital monitoring after initial reactions have been treated, to increase detection of biphasic anaphylaxis (BA). BA is a second wave of symptoms after initial resolution. These guidelines are based on poor or little evidence and have unintended negative impacts on patient safety and quality of life. Furthermore, this 'one-size fits all' approach to care leads to wasteful resource utilization that provides low value care.

OBJECTIVE: The main objective of the study is to derive a clinical prediction rule that identifies children with anaphylaxis who are at risk of BA.

METHODS: This prospective multicenter cohort study will enroll 1682 patients from 7 pediatric EDs that are members of the Pediatric Emergency Research Canada (PERC) network. We will enroll patients < 18 years of age presenting to the ED with an allergic reaction that matches the diagnostic criteria of anaphylaxis. Research assistants (RA) present in the ED will screen, obtain consent, and prospectively collect all study data. The Research Assistant or Research Nurse will follow patients during their ED visit and ascertain, in conjunction with the medical team, if the patient developed biphasic anaphylaxis in the ED. A standardized follow-up survey conducted within 2-5 days of ED or hospital discharge will determine if a biphasic reaction occurred following ED disposition. We established an advisory council comprised of end-users and community partners external to the project team to monitor project milestones.

STUDY TEAM: We have established an international multidisciplinary team of experts in pediatrics, emergency medicine, allergy/immunology, research methodology and statistics, and knowledge translation. Our team is supported by the PERC network.

EXPECTED OUTCOME: Providing the best evidence-based, value care at the lowest cost is a moral and ethical imperative. Therefore, in alignment with national and international research priorities, we propose to develop a robust prediction model for BA. This model will address a significant gap in current knowledge and practice, with anticipated benefit for patient care and health system efficiency worldwide. This trial will generate novel, clinically relevant data on optimal ED management of children with anaphylaxis that integrates best value care with patient safety.

Study Overview

• Status: Active, not recruiting
• Conditions: Anaphylaxis
• Intervention / Treatment: Other: Observational

• Study Type: Observational
• Enrollment (Actual): 1682

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T3B 6A8
      • Alberta Children's Hospital
    • Edmonton, Alberta, Canada, T6G 2C8
      • Stollery Children's Hospital
  • Ontario
    • Hamilton, Ontario, Canada, L8S 4L8
      • McMaster University
    • London, Ontario, Canada, N6A 5W6
      • Children's Hospital of Western Ontario
    • Ottawa, Ontario, Canada, K1H 8L1
      • Children's Hospital of Eastern Ontario
    • Toronto, Ontario, Canada, M5G 1X8
      • The Hospital for Sick Children
  • Quebec
    • Montreal, Quebec, Canada, H3T 1C5
      • Centre Hospitalier Universitaire Sainte-Justine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: No older than 18 years (Child, Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

All patients under the age of 18 who present to the Emergency Department with an allergic reaction that matches diagnostic criteria for anaphylaxis.

Description

Inclusion Criteria:

• Patients < 18 years of age presenting to the ED with an allergic reaction that matches diagnostic criteria for anaphylaxis as defined by the World Allergy Organization (WAO) in 2019. The 2019 WAO anaphylaxis guidelines clarify the involvement of two organ systems to diagnose anaphylaxis, stating that "although the diagnosis of anaphylaxis usually depends on the involvement of multiple organ systems, anaphylaxis may present as an acute cardiac or respiratory event as the only manifestation of anaphylaxis." Thus, a patient with isolated hypotension, bronchospasm, or upper airway obstruction after exposure to a known or potential trigger will be deemed to have anaphylaxis, even if typical skin features are absent.
• Language proficiency in English or French

Exclusion Criteria:

• Anaphylactic reaction that occurred in the context of a suicidal attempt or intoxication
• Anaphylactic reaction that begins in hospital and managed outside ED (on an inpatient or outpatient unit)
• Patient who is unable to complete the follow-up survey post ED discharge.
• Previous enrollment in the CAN-PREPARE Study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Children with Anaphylaxis; Patients under 18 years of age presenting to the Emergency Department (ED) with an allergic reaction that matches diagnostic criteria for anaphylaxis.	Other: Observational; Not applicable - observational study

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of biphasic anaphylaxis	The primary outcome for this prospective cohort study of children who present to ED with anaphylaxis is the development of biphasic anaphylaxis (BA) in the ED or after hospital/ED discharge. As per the published consensus definition in 2019, to be classified as BA, an anaphylactic reaction must meet 3 criteria: 1) initial anaphylactic reaction followed by resolution of all initial manifestations for ≥1 h, with no new symptoms or treatment administered in that time; 2) the second phase of new or recurrent symptoms or signs that meet the consensus definition of anaphylaxis, and 3) the new or recurrent symptoms or signs are not caused by antigen re-exposure. This definition focuses on clinically important or major biphasic reactions. Mild symptoms that involve only the skin (e.g. urticarial rash) without any other systems involvement will be captured and classified as minor biphasic responses. However, these minor responses do not meet our case definition for BA.	Up to 5 days post enrollment

Collaborators and Investigators

• Sponsor: Waleed Alqurashi
• Collaborators: The Hospital for Sick Children; Canadian Institutes of Health Research (CIHR); McMaster University; Alberta Children's Hospital; Stollery Children's Hospital; Children's Hospital of Western Ontario; CHU Ste-Justine, Montreal
• Investigators: Principal Investigator: Amy C Plint, MD, Children's Hospital of Eastern Ontario; Principal Investigator: Waleed Alqurashi, MD, Children's Hospital of Eastern Ontario; Principal Investigator: Marcus S Shaker, MD, Dartmouth-Hitchcock Medical Center

Publications and helpful links

General Publications

• Alqurashi W, Shaker M, Wells GA, Collins GS, Greenhawt M, Curran JA, Zemek R, Schuh S, Ellis A, Gerdts J, Kreviazuk C, Dixon A, Eltorki M, Freedman SB, Gravel J, Poonai N, Worm M, Plint AC. Canadian Anaphylaxis Network-Predicting Recurrence after Emergency Presentation for Allergic REaction (CAN-PREPARE): a prospective, cohort study protocol. BMJ Open. 2022 Oct 31;12(10):e061976. doi: 10.1136/bmjopen-2022-061976.

Helpful Links

• Study Protocol Publication

Study record dates

Study Major Dates

• Study Start (Actual): April 11, 2022
• Primary Completion (Actual): April 16, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: November 11, 2021
• First Submitted That Met QC Criteria: November 23, 2021
• First Posted (Actual): November 26, 2021

Study Record Updates

• Last Update Posted (Actual): April 22, 2025
• Last Update Submitted That Met QC Criteria: April 17, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Biphasic Anaphylaxis
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Immune System Diseases; Hypersensitivity, Immediate; Recurrence; Hypersensitivity; Shock; Anaphylaxis
• Other Study ID Numbers: CTO 3721

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No