Validation of the food allergy quality of life questionnaire series in Chinese families with food-allergic children.

Background: Anxiety from accidental exposure and vigilant dietary monitoring impair the quality of life (QoL) of food-allergic patients. A comprehensive food allergy-specific questionnaire allows patients to accurately report their QoL. This study validated the Food Allergy Quality of Life Questionnaire (FAQLQ) series and assessed the QoL of Chinese food-allergic patients and their caregivers.

Methods: FAQLQ series developed by EuroPrevall consists of four separate questionnaires for parents, children, adolescents and adults. All questionnaires were translated into traditional Chinese by standard forward and backward methods. A cross-sectional study was conducted on food-allergic patients and children's parents using an age-appropriate questionnaire. The performance indices of FAQLQ and their correlation with independent measures of food allergy were analyzed, and factor analysis was performed to confirm the factor structure of FAQLQ questionnaires.

Results: Cross-sectional validation was performed on 214 participants, with 40 reassessed for test-retest reliability. Overall scores for the FAQLQ series had good internal consistency with Cronbach's α ≥.90. Good construct validity was demonstrated by correlations between FAQLQ-Parent Form, FAQLQ-Child Form, FAQLQ-Teenager Form, FAQLQ-Adult Form and Food Allergy Independent Measure (FAIM) scores, except in 0- to 3-year-old children. Test-retest analyses revealed a significant correlation between total FAQLQ score, parent-reported FAIM and food anxiety domain in 4-6 years, and between total score and FAIM in 7-12 years. Exploratory factor analysis categorized items in the FAQLQ series into three to four domains.

Conclusion: FAQLQ series provide a valid and reliable measure for QoL in Chinese food-allergic patients and caregivers, except for parents of children aged 0-3 years. Items for all FAQLQ questionnaires are categorized into different functional domains in our population.