Content Validity of the Hemophilia Device Handling and Preference Assessment Questionnaire - A Cognitive Debrief Study in Patients with Hemophilia and Their Caregivers

As new treatment options using different modes of administration become available for patients with hemophilia, it is important to assess how patients and caregivers perceive the use of different injection systems. This study aimed to evaluate patient comprehension, relevance, and comprehensiveness of the Hemophilia Device Handling and Preference Assessment (HDHPA) instrument among the hemophilia population. Specifically, cognitive interviews were to be conducted to establish evidence of the content validity for the instrument's use in a handling and preference study. This cross-sectional interview study included participants randomly selected from a pen-injector handling and preference study in the USA who had self-administered a ten-item HDHPA questionnaire. Subsequently, semi-structured cognitive interviews were conducted examining HDHPA instrument instructions, items, and response options. The study sample consisted of 20 participants (50% adult patients, 25% adolescents, and 25% caregivers; 75% male). Most participants (89-100%) demonstrated comprehension of the instructions given. Nearly all participants (94-100%) demonstrated clear comprehension of the ten HDHPA items. All 20 participants stated that the questionnaire was relevant and comprehensive in assessing the pen-injector and comparing it to their current device. The results of this study showed that the HDHPA items are comprehensible, relevant, and comprehensive, thereby confirming the content validity of this instrument.