Does Reducing Videofluoroscopy Frame Rate Affect DIGEST Grades in Modified Barium Swallow Studies?

Understanding the effects of reduced frame rates on the reliability of Modified Barium Swallow (MBS) ratings for swallowing safety and efficiency is essential for clinical practice. While previous research has examined frame rate (simulated pulse rates) implications concerning penetration, aspiration, and residue ratings, the impact on summary grading systems like the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) remains unclear. This study analyzed a total of 315 full MBS videos collected from 278 patients, and 76.25% of patients were diagnosed with head and neck cancer (mean age 62.51 years, SD 8.53; 12.23% female). We performed pairwise comparisons of DIGEST grades and DIGEST grade components (Safety and Efficiency) derived independently across studies with 30, 15, and 7.5 frames per second (FPS). Weighted Cohen's kappa values consistently exceeded 0.84 across all assessments, indicating "almost perfect" agreement among the different simulated pulse rates. Exact agreement for all comparisons surpassed 85%. These findings suggest that the DIGEST grading system is robust to variations in frame rate, allowing for reliable assessments even under reduced pulse rate conditions.