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

Prader-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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The author(s) received no specific funding for this work. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Approval for this study was obtained by the Vanderbilt University Institutional Review Board, Integrated Science Committee. Vanderbilt University participants provided written, informed consent using the e-consent function of RedCap, a secure, web-based data collection platform [24]. After consenting, parents were then invited to complete the FSZ, HQ-CT and Demographic questionnaires on RedCap. Additional study approval was obtained for participants recruited from the FPWR Patient Registry. Prior to collecting data from the Registry, the study was reviewed and approved by FPWR’s research committee and internal IRB. All registrants in FPWR’s Patient Registry give approval for their unidentified data to be used for research purposes. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All relevant data are within the manuscript and its Supporting Information files.