Validation of the Food Safe Zone Questionnaire for Families of Individuals with Prader-Willi syndrome

Abstract

AbstractPrader-Willi syndrome (PWS), a genetic neurodevelopmental disorder, is characterized by hyperphagia and significant behavioral problems. Hyperphagic individuals with PWS are chronically hungry yet rarely feel sated, and often engage in food-seeking behaviors. To avoid obesity in their children, families implement food security and supervision strategies (e.g., locking food sources, alerting others). Yet such accommodations may undermine parental appraisals of hyperphgia (e.g., it’s not a problem as we lock food); a potential confound in clinical trials aimed at attenuating hyperphagia. We developed the Food Safe Zone (FSZ) questionnaire to remind parents of their food safety practices prior to them evaluating their child’s hyperphagia.Our team developed 20 FSZ items that were revised for clarity and completeness in an iterative feedback process with stakeholders; parents, PWS specialists, and individuals with PWS. The FSZ was pilot tested, descriptive findings were reviewed by additional stakeholders, and then administered to 624 parents in a large-scale study. Based on an open-ended question, “Is there anything else you do to ensure food safety?” two additional items were added and evaluated in a follow-up study.Principal component analyses revealed that 21 FSZ items loaded onto 5 factors that were readily interpretable, accounting for 67% of test variance: Alerting Others and Food Supervision in the Community; Locking or Restricting Food Sources; Checking for Food; At Home Supervision and Meals; and Avoiding Food Settings. Internal consistency and test-rest reliability were robust. Convergent validity analyses revealed that regardless of age, parents implemented more FSZ strategies in response to the severity of their child’s hyperphagia.The psychometrically sound FSZ stands to enhance accurate parental assessments of hyperphagia in future studies or clinical trials. Analyses of the open-ended question also shine a light on the extraordinary measures that parents use to ensure the health of their individual with PWS.