DIGEST Grades Remain Stable With Inclusion of Moderately Thickened Liquids in the Videofluoroscopic Examination in Individuals With Amyotrophic Lateral Sclerosis

Purpose: The Dynamic Imaging Grade of Swallowing Toxicity (Version 2; DIGEST V2 ) is a videofluoroscopy (VF) scale that measures pharyngeal swallowing severity based on functional measures of swallowing safety and efficiency. Original validation is based on a standard VF testing protocol including thin liquid, puree, and solid consistencies. Given that thickened liquid bolus trials are common in VF clinical testing protocols, we sought to determine the agreement in DIGEST V2 grades with and without the inclusion of moderately thick liquid bolus trials on DIGEST V2 outcomes in people with amyotrophic lateral sclerosis (pALS). Method: This study represents a secondary analysis of VF examinations from a prospective longitudinal study conducted in 109 pALS. VF evaluations contained 10 barium trials spanning three International Dysphagia Diet Standardisation Initiative (IDDSI) levels (0–7). Duplicate, independent, and blinded ratings were completed. DIGEST V2 Efficiency and Safety grading was then completed under two conditions—with and without the inclusion of moderately thick liquid bolus trials into DIGEST V2 grading—to produce two sets of DIGEST V2 ratings for each VF study. Descriptives, percent agreement, and a weighted Cohen's kappa were performed on DIGEST V2 grades. Results: A total of 373 VF examinations were included in this analysis. DIGEST V2 grade percent agreement with and without IDDSI Level 3 was excellent for Safety (98.1%), Efficiency (93.8%), and Total (94.1%) grades. Kappa values for Safety, Efficiency, and Total grades were .96, .89, and .91, respectively, indicating excellent agreement across bolus trial inclusion methods. Conclusions: Standard inclusion of moderately thick liquid bolus trials did not significantly impact DIGEST V2 grading in this data set. These results add to the preliminary but growing evidence suggesting stability of DIGEST grading with alternate bolus protocols in another patient population. Supplemental Material: https://doi.org/10.23641/asha.32348451