Overview of registries for anaphylaxis: a scoping review
Authors: Stiles Samantha L. , Roche Ingrid , Said Maria , Clifford Rhonda M. , Sanfilippo Frank M. , Loh Richard , Salter Sandra M. 
Published: August 2022

ABSTRACT

Objective:
This review aims to describe the scope and operational features of anaphylaxis registries and assess their contribution to improving knowledge of anaphylaxis and care for anaphylaxis patients by measuring their research output.

Introduction:
Structured data collection and reporting systems, such as registries, are needed to better understand the burden of anaphylaxis and protect the growing number of patients with severe allergy. There is a need to characterize current anaphylaxis registries to identify their value in anaphylaxis surveillance, management, and research. Information synthesized in this review will provide knowledge on benefits and gaps in current registries, which may inform the implementation and global standardization of future anaphylaxis reporting systems.

Inclusion criteria:
This scoping review considered literature describing registries worldwide that enroll patients who have experienced anaphylaxis. Published and gray literature sources were included if they described the scope and operational features of anaphylaxis registries. Only full-text studies in English were considered for inclusion.

Methods:
This review followed the JBI methodology for scoping reviews. Embase, MEDLINE, Scopus, and CINAHL were searched for relevant articles. Identified keywords and index terms were adapted for searches of gray literature sources, using Google advanced search functions. Two independent reviewers conducted title and abstract screening and those that did not meet the inclusion criteria were excluded. The full text of potentially relevant articles were retrieved; full-text screening and data extraction were also conducted by two independent reviewers. Any discrepancies were resolved through discussion or with a third reviewer. Tables and a narrative summary were used to describe and compare the scope and features (eg, inclusion criteria, patient demographics, clinical symptoms) of the identified anaphylaxis registries and outline their output to assess their contribution to research and clinical practice for anaphylaxis.

Results:
A total of 77 full-text publications and eight gray literature sources were used to extract data. The literature search identified 19 anaphylaxis registries, with sites in 28 countries including Europe, the United Kingdom, Canada, the United States of America, Korea, and Australia. The main purposes of the identified registries were to collect clinical data for research; provide clinical support tools to improve patient care; and operate as allergen surveillance systems to protect the wider community with allergies. Differences in inclusion and health care settings exist, with 11 collecting data on anaphylaxis of any cause, two on food reactions alone, three on fatal anaphylaxis, one on perioperative anaphylaxis and two on allergic reactions (including anaphylaxis). Five registries enroll cases in allergy centers, five in hospital settings, one in schools, and others target a combination of general practitioners, specialists in emergency departments, and other relevant hospital departments and allergy outpatient clinics. Only three registries operate under a mandatory framework. A total of 57 publications were considered research outputs from registries. All registries except for two have published studies from collected data, with the greatest number of articles published from 2019 to the present. Publications mostly addressed questions regarding demographic profile, causes and cofactors, severity, fatal reactions, and gaps in management.

Conclusions:
This review demonstrated that anaphylaxis registries currently differ in their scope and operation, having been established for different purposes. Importantly, registries have contributed significantly to research, which has highlighted gaps in anaphylaxis management, provoking allergens, and informed targets for prevention for severe and fatal events. Beyond this, registries relay information about anaphylaxis to clinicians and regulatory bodies to improve patient care and protect the community. The ability to link registry data with other health datasets, standardization of data across registries, and incorporation of clinical care indicators to promote quality health care across the health system represent important targets for future systems.