OBJECTIVES: Limited normative reference data are available for validated outcomes of flexible endoscopic evaluation of swallowing (FEES). We aimed to examine healthy swallowing via FEES in community-dwelling healthy adults to derive a preliminary reference dataset of normative validated FEES outcomes to guide clinical interpretation and diagnostic decision-making. METHODS: Adults with no history of dysphagia-related disease underwent simultaneous videofluoroscopy and FEES imaging using a standardized 11-item bolus protocol. Trained raters performed duplicate, independent, blinded ratings of the New Zealand Secretion Scale (NZSS), Penetration-Aspiration Scale (PAS), and Dynamic Imaging Grade of Swallowing Toxicity-FEES (DIGEST-FEES) validated scales. Descriptive statistics were performed at the bolus (PAS) and participant level (NZSS, DIGEST-FEES). RESULTS: 361 swallows from 33 community-dwelling adults (36.6 ± 14.7 years old) were analyzed. In rank order, distribution profiles were: (1) NZSS: 95% normal (NZSS = 0), 5% abnormal (NZSS = 4)
(2) Worst PAS: 73% safe (PAS 1-2, n = 24), 21% penetration above the true vocal folds (PAS 3, n = 7), 6% deep penetration to the true vocal folds (PAS = 5, n = 2)
(3) DIGEST-FEES Safety Grades: 91% Grade 0 (normal, n = 30), 9% Grade 1 (mild impairment, n = 3)
(4) DIGEST-FEES Efficiency Grades: 73% Grade 0 (normal, n = 24), 24% Grade 1 (mild impairment, n = 8), 3% Grade 2 (moderate impairment, n = 1). CONCLUSION: This preliminary healthy FEES dataset highlights variation in swallowing safety and efficiency and suggests careful interpretation of FEES outcomes to avoid over-pathologizing impairment. Future studies are warranted to obtain additional normative data in diverse populations to further understand normal variation in FEES outcomes to guide clinically meaningful diagnostic cut-points. LEVEL OF EVIDENCE: 3 Laryngoscope, 135:1034-1038, 2025.