Roadmap of Anaphylaxis Registries Across the World

SUMMARY Medical registries provide highly reliable real-world data on epidemiology but have also evolved to disease prevention, early diagnosis and screening programmes, treatment response, healthcare planning, decision making and disease control programmes [1, 2]. The main uses of medical registries usually include patient care (improvement of care quality, outcome and effectiveness of treatment, monitoring risk groups and providing risk stratification), public health (assessment of disease burden, healthcare policies), technology assessment of biopharmaceutical products or medical devices and research. Patient registries can be useful to interact with health authorities to improve public health at a national level and to alert participants and clinicians on new insights about disease, unexpected and adverse effects, and medical products, improve clinical care. In the field of anaphylaxis, patient registries inform epidemiology, management and research [1, 2]. There are only scarce data about ongoing anaphylaxis registries and their framework. Our article aims to identify and describe the scope and features of worldwide registries collecting data related to anaphylaxis. We defined a patient anaphylaxis registry as a collection – for one or more purposes – of standardised information about patients who experienced anaphylaxis. An online questionnaire was prepared and validated by independent experts in the field of anaphylaxis. It was made available through the LimeSurveyR platform, beta-tested and launched by e-mail to worldwide health professionals from the World Allergy Organisation (April–September 2024) with three follow-up reminders. The questionnaire covered geographical coverage, methods to collect data, sources of data validation, extraction and funding. All responses were anonymous and voluntary. Only one response per e-mail was permitted. This survey did not require any ethics committee approval. Responses were received from 293 members, representing 67 countries, of whom 95 (32.4%) from 45 countries reported recording data for at least one anaphylaxis registry. Participants declared they collect data at a national (23/49; 47%) or international level (19/49; 39%), for anaphylaxis of any cause in 72/88 (82%) and for fatal anaphylaxis in 32/88 (36%). Allergists (88%) and emergency physicians (34%) were the most frequent participants of the registry involved in data collection. Sixteen anaphylaxis registries have been identified (Table 1). These registries were mainly located in Europe (n = 6), regions of Asia (n = 4), Australia (n = 1), Latin America countries (n = 3) and North America (Canada, United States) (n = 2). Of the 16, 10 (63%) registries were nation-based, four (25%) were international, and two (13%) covered a regional population. Thirteen (81%) registries collected data on anaphylaxis of any cause, two (13%) on drug-related anaphylaxis (including one in the perioperative setting) and 1 on reactions after subcutaneous allergen immunotherapy. All but one registry included cases of all ages, with a single registry enrolling only paediatric cases. Six (38%) collected cases from hospital settings (emergency settings/allergy departments) and the others from a combination of various settings, including private practice and hospital settings. Three registries (19%) operate under a mandatory framework. Patients' consent for participation was required in only one registry. Funding sources were mainly governmental (n = 6), private (n = 4) or provided by academic allergy societies (n = 3). Based on the literature research, a previous review identified 19 anaphylaxis registries worldwide, which generated 77 full-text publications [3, 4]. Comparing our findings with those reported by Stiles et al., we observed that the main locations of the registries were similar. We found that most registries were nation-based, with four at an international level, whereas Stiles et al. reported that eleven out of 19 were nation-based and two international. The main purpose, data collection for anaphylaxis of any cause, was quite similar in both studies. However, we did not identify any registry dedicated to fatal anaphylaxis; Stiles et al. reported three anaphylaxis registries focusing on fatal cases. According to our results, there was a wide variety of funding sources which are one major pitfall regarding the creation, development, and sustainability of patient registries. Additionally, only three out of 16 registries were operating under a mandatory framework, consistent with previous reports [4]. Surprisingly, we found that informed consent from subjects was obtained in only one registry. The main limitation of our study is that we could not identify all anaphylaxis registries, and it is likely that some ongoing registries were not included. Our study counted on volunteer responses and should be viewed as a snapshot in time, reflecting the variety of anaphylaxis registries worldwide, rather than an exhaustive overview of this topic. We identified a wide range of anaphylaxis registries, six in Europe, with differences in scope, organisation, and funding sources. Anaphylaxis registries are of a major importance to provide real-world data about risk factors for severity and recurrences (e.g., for specific anaphylaxis triggers, as for foods or drugs), develop healthcare cost mitigation strategies (e.g., stocking adrenaline auto-injectors in schools), improve or harmonise quality and outcome measures (e.g., anaphylaxis severity scores) [1, 2]. Challenges in the development of these medical registries include data quantity, reliability and consistency [1, 2]. Structuring, coding and integrating data from diverse sources remain significant hurdles, and standardisation of the different sources is crucial. Registries should evolve into a new generation of integrated systems within a ‘big data’ health information framework, including data from electronic health records and hospital operators, leveraging advancements in semantic web technology [5]. A close collaboration between allergists involved in clinical research and anaphylaxis registries is required. G.P. analysed, interpreted the data and wrote the draft. D.P.C. and L.K.T. performed the electronic survey using the LimeSurvey platform. F.D., S.L., D.P.C., P.M.M., C.T., S.L., P.D., and L.K.T. were major contributors in reviewing the draft and improving the paper with critical analysis. All authors read and approved the final manuscript. We acknowledge all participants of this electronic survey. G.P. has provided consultation and speaker services for AImmune Therapeutics, Stallergenes, Novartis, DVB technology, ALK-Abello, Viatris and Bioprojet; serves as a medical consultant/advisor for Bioprojet, Theravia and Viatris. DPC declares personal fees from Sanofi and GlaxoSmithKline and congress support from Sanofi, Stallergènes, ALKAbelló, AstraZeneca and Viatris outside the submitted work. The other authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.