Time as a factor during endoscopic assessment of swallowing: relevance in defining the score and severity of swallowing disorders

Time is a parameter of great interest in swallowing and can be considered in different ways to express severity during endoscopic evaluation. The objectives of this study are to evaluate how the severity of this score changes at different times of scoring and the interaction between residue persistence and airway invasion. Two experienced raters blindly evaluated 35 short clips of bolus transit that were recorded during endoscopic evaluations of 16 patients with dysphagia of differing aetiologies. The pooling score (p-score) and the Penetration Aspiration Scale (PAS) were detected after the first swallowing (T1) and after the fifth dry swallow (T5). For each task, the time needed to complete the clearing of the bolus (total time: TT) was blindly determined by the two raters and compared with the Functional Oral Intake Scale (FOIS) and Dysphagia Outcome and Severity Scale (DOSS) scales, previously detected.The inter-rater agreement between the 2 raters in scoring the p-score and PAS was good (ICC > 0.800) for T1 vs T1 and T1 vs T5, and in determining TT for each consistency (ICC > 0.9), with a Spearman’s Rho > 0.70 and > 0.90 respectively. A statistical correlation of the p-score total, TT and consistency with FOIS and DOSS was found. The p-score showed a good trade-off between sensitivity and specificity compared with the PAS aspiration and penetration scores. The time of scoring (T1 vs T5) is relevant in detecting severity of dysphagia during endoscopic evaluation. The time spent to clear residue is a useful parameter and is correlated with severity of dysphagia expressed by the p-score and with functional swallowing status in dysphagic patients. The p-score is correlated with the PAS score in detecting airway invasion.