Reliability of a High-Speed Videoendoscopy Protocol for Swallowing Analysis

To investigate the reliability of high-speed videoendoscopy (HSV) methodology for quantifying laryngeal swallowing behaviors.

Twenty-two healthy adults completed a dry volitional swallow under HSV at 500 frames per second (fps) with a lower-than-standard scope position located in the laryngeal vestibule. After reaching consensus among five raters on specified behaviors and definitions, all raters used a custom MATLAB graphical user interface (GUI) to annotate the laryngeal behaviors during the pharyngeal phase of the swallow and rated their confidence in visualizing laryngeal anatomy and movements. Inter- and intra-rater reliability for timing of the onsets, offsets, and durations of each laryngeal behavior was calculated using intraclass correlation coefficients (ICCs), and presence/absence agreement of each behavior was quantified by Fleiss's kappa and supplemented with percent agreement.

Raters reported confidence visualizing the vocal folds (87%) and the arytenoids (80%). Full arytenoid closure was present in 84%, while full anterior-posterior compression had the highest inability-to-visualize rate (41%). Inter-rater reliability was good to excellent for onset (ICC range, 0.82-0.99), excellent for offset (0.91-0.99), and poor to moderate for duration (0.08-0.63). Percent agreement for presence/absence exceeded 80% across all behaviors. Intra-rater reliability was good to excellent for onset (0.85-0.99), excellent for offset (0.91-0.99), and poor to moderate for duration (0.14-0.60).

HSV, with a standardized low-scope protocol and analysis using a custom GUI with clear definitions, is a promising, feasible, and reliable tool for investigating onset and offset timings of specific laryngeal patterns during the pharyngeal swallow.