Inter-rater reliability of Videofluoroscopic dysphagia scale

Objective: To investigate the inter-rater agreement using the Videofluoroscopic Dysphagia Scale (VDS). Method: The present study was designed as a multicenter, single-blind trial. A Videofluoroscopic Swallowing Study (VFSS) was performed using the protocol described by J.A Logemann. Thick-fluid, pureed food, mechanically altered food, regularly textured food, and thin-fluid boluses were sequentially swallowed. Each participant received a 3 ml bolus followed by a 5 ml bolus of each food material, in the order mentioned above. All study procedures were video recorded. Discs containing these video recordings in random order were distributed to interpreters who were blinded to the participant information. The video recordings were evaluated using a standardized VDS sheet and the inter-rater reliability was calculated. Results: In total, 100 patients participated in this study and 10 interpreters analyzed the findings. Inter-rater reliability was fair in terms of lip closure (k: 0.325), oral transit time (0.253), delayed triggering of pharyngeal swallowing (0.300), vallecular residue (0.275), laryngeal elevation (0.345), pyriform sinus residue (0.310), coating of the pharyngeal wall (0.310), and aspiration (0.393). However, other parameters of the oral phase were lower than those of the pharyngeal phase (0.06-0.153). Moreover, the summation of VDS reliability (intraclass correlation coefficient: 0.556) showed moderate agreement. Conclusion: VDS shows a moderate rate of agreement for evaluating the swallowing function. However, many of the parameters demonstrated a lower rate of agreement, particularly the oral phase parameters.