Development of the Hyperphagia Questionnaire for use in Prader-Willi syndrome clinical trials
OBJECTIVES: The Hyperphagia Questionnaire (HQ) is a well-established, caregiver-reported questionnaire that focuses on food-seeking behaviors common among individuals with Prader-Willi syndrome (PWS). The goal of this research was to develop and psychometrically evaluate a modified version of the HQ for use within PWS clinical trials. METHODS: Following modification of the HQ based on industry and regulatory standards (e.g., Food and Drug Administration, 2009), the initial, 10-item version of the HQ for Clinical Trials (HQ-CT) was used in a phase 2 trial with the resulting data analyzed to identify the optimal scoring approach and evaluate instrument psychometric properties. Next, further evaluation by clinical experts in PWS and regulatory authorities resulted in removal of an item that focused more on patient-caregiver interactions than direct observation of patient behavior. Qualitative interviews were then conducted with PWS caregivers to inform final refinements, provide additional support for content validity, and assess usability of the electronic (ePRO) version of the 9-item measure. RESULTS: Initial modifications to the HQ reduced the recall period, optimized response scales, and limited item content to observable behaviors that have the potential to change during the course of a clinical trial. Psychometric evaluation supported the use of a single HQ-CT composite score as well as the questionnaire’s reliability and validity. The HQ-CT total score was also able to demonstrate improvements in hyperphagia-related behavior between treatment groups. Finally, qualitative interviews with 6 caregivers supported the relevance and comprehensiveness of the content, item clarity, and the ePRO version of the HQ-CT’s ease of use. CONCLUSIONS: Qualitative and quantitative evidence provide support for use of the 9-item HQ-CT total score for the assessment of food-seeking behaviors in PWS clinical trials. The HQ-CT is currently being used in a phase 3 PWS study.