Methodology of the international cross-sectional prevalence and severity study of pediatric and adult IgE-mediated food allergies (ASSESS FA).

Background: The burden and prevalence of food allergy (FA), a condition known to negatively impact the quality of life (QoL) of patients and their families, vary across countries due to cultural habits and clinical practices and have been assessed differently among previous studies. To date, no validated scale exists to measure FA severity risk. Objective: The study objectives were to develop a standardized methodology to estimate FA point prevalence in children and adults in 9 countries, to assess FA impact on QoL, and to construct a framework to define FA severity risk based on QoL and FA clinical severity. Methods: This was a cross-sectional, international study that collected self-reported data through an online quantitative survey. Participants were recruited from general population panels: parents/caregivers of children aged 6 months-17 years, and adults aged 18-65 years. The survey instrument was developed by a panel of clinical FA experts and epidemiologists. Results: Weighted prevalence rates were calculated for the 4 generated case definitions of FA (self-reported, physician-diagnosed, symptom-convincing, and confirmed FA). Several validated scales, including the Food Allergy Quality of Life Questionnaire (FAQLQ) and the Food Allergy Independent Measure (FAIM), were used to assess FA impact on QoL in patients with symptom-convincing FA. Four FA severity risk profiles were generated: non-severe, at-risk, highly impacted QoL, and severe patients. Conclusion: The ASSESS FA study developed a methodology to estimate the prevalence of FA and its impact on QoL consistently across countries, age groups, and food allergens. The severity risk framework was based on both the clinical severity and impact on QoL aspects of FA.