Development of a questionnaire to measure quality of life in families with a child with food allergy

Background: Food allergy is potentially severe, affects approximately 5% of children, and requires numerous measures for food avoidance to maintain health. The effect of this disease on health-related quality of life (HRQL) has been documented by using generic instruments, but no disease-specific instrument is available. Objective: To create a validated, food allergy-specific HRQL instrument to measure parental burden associated with having a child with food allergy: the Food Allergy Quality of Life-Parental Burden questionnaire. Methods: After identification of 74 items affecting families with children with food allergy, 88 families were approached for effect scoring. Final items were generated by score results, elimination of redundancies, and content review. Resulting high-effect areas were queried for validation with a 7-point Likert scale. A final instrument including 17 items and 2 expectation of outcome questions was distributed to 352 families for validation. Results: Areas of effect included family/social activities (restaurant meals, social activities, child care, vacation), school, time for meal preparation, health concerns, and emotional issues. Validation steps showed strong internal validity (Cronbach alpha, 0.95) and good correlation with expectation of outcome questions (r = 0.412; P < .01) and scores on a generic HRQL instrument, the Children's Health Questionnaire-PF50. (r = -0.36 to -0.4; P < .01). The instrument showed the ability to discriminate by disease burden: parents whose children had multiple (>2) food allergies were more affected than parents whose children had fewer allergies (scores, 3.1 vs 2.6; P < .001). Conclusions: The Food Allergy Quality of Life-Parental Burden demonstrates strong internal and cross-sectional validity. Its discriminative ability suggests that it will be a useful tool to measure outcomes in treatment studies of food allergy for children.