Improving Severity Scoring of Food-Induced Allergic Reactions: A Global “Best-Worst Scaling” Exercise

Aisling Stafford,Joan Bartra,Antony Aston,E N Clare Mills,Montserrat Fernandez-Rivas,Paul J Turner

doi:10.1016/j.jaip.2021.06.056

Abstract

BackgroundThere is no current consensus on assigning severity to food-induced allergic reactions, for example, to assess the efficacy of allergen immunotherapy. Existing severity scores lack the capability to discriminate between non-anaphylaxis reactions of different severities. Attempts are ongoing to develop a more discriminatory score, which should ideally be data-driven and validated in multiple cohorts.ObjectiveTo undertake an exercise using best-worst scaling (BWS) to define a potential gold standard against which severity scoring of food-induced allergic reactions can be refined.MethodsWe undertook a global survey to better understand how health care professionals rate the severity of food-induced allergic reactions, using BWS methodology. Respondents were given a number of patient case vignettes describing real-world allergic reactions and asked to select the pair that, in their opinion, reflected the maximum difference in severity. Responses were then modeled and a preference score (representing severity) determined for each scenario. Scenarios were also scored using existing published scoring systems and the scores compared with the BWS score using Spearman r correlation and Cohen kappa. Given the differences in definitions of anaphylaxis globally, we also evaluated differences in BWS ranking depending on the geographical location of respondents.ResultsWe received 334 complete responses, 183 (55%) from Europe and 65 (20%) from North America. Perception of severity of some reactions appeared to be affected by geographical location. The comparison of BWS ranking with current grading systems identified significant issues that varied from one grading system to another, such as prominence to some symptoms (eg, vomiting) that skew grading when using scoring systems not designed for food allergy. In general, current scoring systems poorly discriminate against more mild symptoms and often overestimate their severity.ConclusionsThese data provide a methodology free of user scale bias to help define a potential, consensus-driven gold standard that can be used to guide and validate the development of improved grading systems to score food-induced allergic symptoms and highlight areas for education where there is the potential to miscategorize severity.

Highlights

Immunoglobulin Eemediated allergic reactions form a spectrum of severity, from very mild self-limiting subjective symptoms to potentially life-threatening anaphylaxis.[1]
SUMMARY Through a global best-worst scaling (BWS) exercise, we identified a number of significant limitations with existing severity scores used to grade food-induced allergic reactions, which varied from one score to another
Increasing our ability to accurately and consistently assign severity should lead to improvements in the management of patients with food allergy

Summary

Introduction

Immunoglobulin Eemediated allergic reactions form a spectrum of severity, from very mild self-limiting subjective symptoms to potentially life-threatening anaphylaxis.[1]. The increasing acceptance of allergen immunotherapy as a treatment modality for food allergy has highlighted the need for a validated symptom grading system to assess the impact of treatment on symptoms following allergen exposure (and not just an effect on allergen thresholds—the dose needed to trigger allergic symptoms). There is no current consensus on assigning severity to food-induced allergic reactions, for example, to assess the efficacy of allergen immunotherapy. OBJECTIVE: To undertake an exercise using best-worst scaling (BWS) to define a potential gold standard against which severity scoring of food-induced allergic reactions can be refined. METHODS: We undertook a global survey to better understand how health care professionals rate the severity of food-induced allergic reactions, using BWS methodology. Given the differences in definitions of anaphylaxis globally, we evaluated differences in BWS ranking depending on the geographical location of respondents. The comparison of BWS ranking with current grading systems identified significant issues that varied aNational Heart and Lung Institute, Imperial College London, London, United Kingdom bHospital Clínic de Barcelona, Barcelona, Spain cDepartment of Paediatric Allergy, The Royal London HospitaleBarts Health NHS

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