The FEES Dysphagia Index: a bias-resilient continuous score that captures expert clinical judgment in 2,943 neurological inpatients

Journal of Neurology, vol. 273

Abstract

Multi-consistency testing during flexible endoscopic evaluation of swallowing (FEES) is clinically necessary, but introduces selection bias: worst scores inflate severity because the number of consistencies tested covaries with disease severity. In this retrospective observational study of hospitalized neurological patients, we derived and validated the FEES Dysphagia Index (FDI) in two temporally independent cohorts (Cohort 1: 2013-2018, N = 1,257; Cohort 2: 2021-2025, N = 1,686) from a single center. FDI-S averages Penetration-Aspiration Scale (PAS) scores across tested consistencies (0-100 scale); FDI-E uses Yale Pharyngeal Residue scores; FDI-C combines both. Selection bias was quantified using sequential branching-tree inverse probability weighting (IPW). Worst PAS overestimated severity by 24%; FDI deviated by < 2%. FDI-C was significantly superior to Worst PAS for hospital-acquired pneumonia (HAP; AUC 0.70 vs. 0.60, p < 0.001), mortality (0.71 vs. 0.62, p = 0.040), and restricted oral intake (0.90 vs. 0.74, p < 0.001), and statistically equivalent to clinician-rated severity. FDI-C mapped linearly onto ordinal Functional Oral Intake Scale values (FOIS; proportional odds RCS p = 0.99). With functional status and diagnosis, FDI-C reconstructed the clinician's oral intake recommendation with AUC up to 0.93. The FDI-C-mortality relationship was sigmoidal with a clinically relevant transition zone between ~ 50 and ~ 85. FDI-C is a bias-resilient, bedside-calculable score with interval-scale properties that captures expert clinical judgment, suitable as both a clinical decision support tool and a continuous research endpoint.

Authors 7

1. Cornelius J. Werner corresponding Aachen Department of Neurology, Medical Faculty Department of Neurology and Geriatrics

   RWTH Aachen University

   Affiliation as printed

   Department of Neurology and Geriatrics, Johanniter-Hospital Stendal, Stendal, Germany. cornelius.werner@rwth-aachen.de

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany. cornelius.werner@rwth-aachen.de

2. Elisabet Sanchez-Garcia

   Cork University Hospital

   Affiliation as printed

   Department of Geriatric Medicine, Cork University Hospital, Cork, Ireland

3. Bettina Mall Aachen Department of Neurology, Medical Faculty

   RWTH Aachen University

   Affiliation as printed

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany

4. Tareq Meyer Aachen Department of Neurology, Medical Faculty

   RWTH Aachen University

   Affiliation as printed

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany

5. João Pinho Aachen Department of Neurology, Medical Faculty

   RWTH Aachen University

   Affiliation as printed

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany

6. Joerg B. Schulz Aachen Department of Neurology, Medical Faculty

   RWTH Aachen University

   Affiliation as printed

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany

7. Beate Schumann‐Werner Aachen Department of Neurology, Medical Faculty

   RWTH Aachen University · Otto-von-Guericke-Universität Magdeburg

   Affiliation as printed

   Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany

   Institute of Cognitive Neurology and Dementia Research (IKND), Otto von Guericke University Magdeburg, Magdeburg, Germany