Development of a Visuoperceptual Measure for Fiberoptic Endoscopic Evaluation of Swallowing (V-FEES) in Adults with Oropharyngeal Dysphagia: An International Delphi Study

Visuoperceptual evaluation of fiberoptic endoscopic evaluation of swallowing (FEES) is a commonly used assessment in dysphagia or swallowing disorders. Currently, no international consensus exists regarding which visuoperceptual measures to use for the analysis of FEES recordings. Moreover, existing visuoperceptual FEES measures are limited by poor and incomplete psychometric data, identifying an urgent need for developing a visuoperceptual measure to interpret FEES recordings. Following the COSMIN group's (COnsensus-based Standards for the selection of health Measurement INstruments) psychometric taxonomy and guidelines, this study aimed to establish the content validity of a new visuoperceptual FEES (V-FEES) measure in adults with oropharyngeal dysphagia. Using the Delphi technique, international consensus was achieved among dysphagia experts across 21 countries, resulting in a new prototype measure for V-FEES, comprising 30 items, 8 function testing items (i.e., specific tasks performed by patients while observing and rating items), and 36 unique operationalisations (i.e., defining items into measurable factors that could be measured empirically using visuoperceptual observation). This study supports good content validity for V-FEES, including participants' feedback on the relevance, comprehensiveness, and comprehensibility of the included items. Future studies will continue the instrument development process and determine the remaining psychometric properties using both the classic test theory (CTT) and item response theory (IRT) models.