Validation of non-instrumental clinical outcome assessments for dysphagia in OPMD: A structured, COSMIN-guided...

Evidence supporting the use of non-instrumental dysphagia outcome measures in people living with oculopharyngeal muscular dystrophy (OPMD) remains limited. This COSMIN-guided validation study evaluated patient-reported and performance-based dysphagia measures in adults with OPMD. Participants completed the Dysphagiameter-OPMD, the Sydney Swallow Questionnaire (SSQ), and the Eating Assessment Tool-10 (EAT-10), along with performance-based swallowing assessments including the 80-mL water drinking test, used as the comparator, 80-mL thickened juice test, and 10.5-g cheese test. Construct validity, internal consistency, intra- and inter-rater reliability, and measurement error were evaluated. Construct validity was supported for all PROMs and PerfOMs, with ≥ 75% of predefined hypotheses confirmed. Reliability was generally good to excellent, with ICC ≥ 0.80 for most PROMs and > 0.90 for all perfOMs, although estimates for the drinking tests were influenced by extreme observations and the limited representation of longer completion times. The thickened juice test showed a small systematic intra-rater bias and provided limited added value over the water test, while agreement estimates for the cheese test were sensitive to extreme observations. Overall, findings provide evidence supporting the validity and the reliability of OPMD-specific PROMs and selected performance-based measures, while highlighting their complementary roles in swallowing outcome assessment.