Intra- and inter-rater reliability of hyoid displacement measured by ultrasound

Purpose: Anterior hyoid displacement is essential for effective swallowing, and is most frequently investigated with video fluoroscopy. Ultrasound offers a less expensive and less invasive method of investigation with high reliability of measurement reported in theliterature1,2. The present pilot study investigated the intra- and interrater reliability of measuring timing and degree of maximal hyoiddis placement. Methods: Three raters reviewed the ultrasound video sweep of 5swallows, from each of 5 participants and the primary investigator measured each sample on two occasions. Identified from each sweep was a ‘rest’ frame prior to the swallow of interest and a ‘maximal displacement’ frame, at which the hyoid bone was at maximal anterior displacement during each swallow. Electronic callipers were used to measure the distance between the mental spine of the mandible and the intersection of the hyoid shadow and the geniohyoid muscle, for both the rest and maximal displacement frames. Results: Single-measure intraclass correlation (ICC) was high forinter-rater agreement at .861 for rest measures and .899 for maximal displacement. Intra-rater reliability was even higher at .949 for rest hyoid measures and .979 for maximal displacement. ICC also showed high inter-rater agreement on the frame of maximal displacement at.974. Conclusion: These results suggest that raters can achieve high agreement regarding measures of maximal hyoid displacement for both identification of peak hyoid displacement and distance of hyoid from mandibular spine. 1. Chi-Fishman, G., & Sonies, B. C. (2002a).Dysphagia, 17(4), 278–287. 2. Chi-Fishman, G., & Sonies, B. C.(2002b). J Speech Lang Hear Res, 45(3), 457–468.