Design and validity of the Spanish version of two questionnaires related to adverse reactions to foodstuffs.

Introduction: there is an emerging current necessity of valid questionnaires, encompassing most of food, beverages, diseases, signs and symptoms currently related to the pathogenesis of adverse reactions to foodstuffs (ARFS) in the Spanish population. Objectives: this study aimed to design and validate two questionnaires to assess ARFS in the Spanish population, Food and Beverages Frequency Consumption Questionnaire to Identify Adverse Reactions to Foodstuffs (FBFC-ARFSQ-18); and Pathologies and Symptomatology Questionnaire associated with Adverse Reactions to Foodstuffs (PSIMP-ARFSQ-10). Methods: both questionnaires were designed adapting questionnaires from the literature; and validated, using the expert judgment method, in five phases: questionnaires development, pilot test and reliability, content validity, face validity, and ethical considerations. Questionnaires were developed using the REDCap™ tool hosted at the Universidad Politécnica de Madrid. A total of 20 Spanish experts evaluated the questionnaires. Cronbach's alpha reliability coefficients were calculated using SPSS version 25.0 (IBM Corp., Armonk, NY-USA) and Aiken's V coefficient values were calculated using ICaiken.exe (Visual Basic 6.0, Lima-Perú). Results: a final construct of questions was designed, ensuring no overlap, for FBFC-ARFSQ-18 and PSIMP-ARFSQ-10. Cronbach's alpha reliability coefficients were 0.93 and 0.94; and Aiken's V coefficient values were 0.90 (0.78-0.96 CI) and 0.93 (0.81-0.98 CI) for FBFC-ARFSQ-18 and PSIMP-ARFSQ-10, respectively. Conclusions: both validated questionnaires could be used to analyze the association between certain food and beverages consumption with ARFS, such as food allergies and food intolerances; also, to investigate the link between some specific diseases, signs and symptoms with ARFS.