Pharyngeal Residue Severity Rating Scales Based on Fiberoptic Endoscopic Evaluation of Swallowing: A Systematic Review

Identification of pharyngeal residue severity located in the valleculae and pyriform sinuses has always been a primary goal during fiberoptic endoscopic evaluation of swallowing (FEES). Pharyngeal residue is a clinical sign of potential prandial aspiration making an accurate description of its severity an important but difficult challenge. A reliable, validated, and generalizable pharyngeal residue severity rating scale for FEES would be beneficial. A systematic review of the published English language literature since 1995 was conducted to determine the quality of existing pharyngeal residue severity rating scales based on FEES. Databases were searched using controlled vocabulary words and synonymous free text words for topics of interest (deglutition disorders, pharyngeal residue, endoscopy, videofluoroscopy, fiberoptic technology, aspiration, etc.) and outcomes of interest (scores, scales, grades, tests, FEES, etc.). Search strategies were adjusted for syntax appropriate for each database/platform. Data sources included MEDLINE (OvidSP 1946–April Week 3 2015), Embase (OvidSP 1974–2015 April 20), Scopus (Elsevier), and the unindexed material in PubMed (NLM/NIH) were searched for relevant articles. Supplementary efforts to identify studies included checking reference lists of articles retrieved. Scales were compared using qualitative properties (sample size, severity definitions, number of raters, and raters’ experience and training) and psychometric analyses (randomization, intra- and inter-rater reliability, and construct validity). Seven articles describing pharyngeal residue severity rating scales met inclusion criteria. Six of seven scales had insufficient data to support their use as evidenced by methodological weaknesses with both qualitative properties and psychometric analyses. There is a need for qualitative and psychometrically reliable, validated, and generalizable pharyngeal residue severity rating scales that are anatomically specific, image-based, and easily learned by both novice and experienced clinicians. Only the Yale Pharyngeal Residue Severity Rating Scale, an anatomically defined and image-based tool, met all qualitative and psychometric criteria necessary for a valid, reliable, and generalizable vallecula and pyriform sinus severity rating scale based on FEES.