Real world safety and efficacy outcomes during oral immunotherapy with characterised peanut protein

Abstract

Food allergy quality of life questionnaires (FAQLQ) are the most common instruments used in food allergy research to assess health-related quality of life (HRQL). With the increase in food allergy treatment trials, it is important to determine which items within the FAQLQ are most and least useful in this context. We sought to assess which items of the FAQLQ-child form (CF) were most discriminative, using item response theory (IRT), which examines relations between item responses and underlying construct (in this case, HRQL). METHODS: PEPITES was a phase 3 randomised, placebo-controlled trial that studied the safety and efficacy of Viaskin Peanut 250 mg in children aged 4-11 years. Children who participated in PEPITES, aged ≥8 years, completed the FAQLQ-CF at baseline and at 12 months. FAQLQ-CF items were analysed using IRT, considering items' discrimination values, difficulty levels, and item information curve. RESULTS: 92 children (mean age 5 8.47 years, SD 1.7) completed the FAQLQ-CF. By IRT analysis, 14 of 30 total items contained in the FAQLQ presented very high discrimination levels (a > 1.7), with the highest levels relating to items that assessed 'fear'. All the items presented difficulty level within the recommended range (mean across b1-b6 < 2+1.5), being neither too easy, nor too difficult. CONCLUSIONS: We have identified 14 items contained within the FAQLQ-CF by IRT approach that best discriminate and assess HRQL in a treatment context. These findings may provide a novel and reliable framework for measurement of changes in HRQL in future food immunotherapy clinical trials.