Measurement Techniques and Properties of Single-item Measures for the Evaluation of Oropharyngeal Muscle Function in Adults with Dysphagia: A Systematic Review using the COSMIN Framework.

Abstract

Muscle dysfunction is a critical construct in dysphagia. Despite the availability of diverse techniques to evaluate muscle function, a comprehensive synthesis of measurement items and their properties is lacking. A systematic review of studies examining the measurement techniques used to directly evaluate oropharyngeal muscle function was performed. Studies investigating the use of surface electromyography, tongue dynamometry, ultrasound, high-resolution pharyngeal manometry, magnetic resonance imaging and computed tomography and reporting measurement properties in line with the COnsensus-based Standards for the selection of health Measurement InstrumeNts (COSMIN) were included. Measurement outcomes derived from these techniques were operationalised as single-item measures. Methodological quality was evaluated using the QualSyst tool. From the 6279 records, 125 eligible studies were identified. The breakdown of techniques was surface electromyography (n = 33), tongue dynamometry (n = 34), ultrasound (n = 17), high-resolution pharyngeal manometry (n = 15), magnetic resonance imaging (n = 5), computed tomography (n = 4) and combined techniques (n = 17). Single-item measures were heterogenous, covering a range of domains including muscle activation, coordination, strength, endurance, composition, thickness, and kinematics. Studies focused predominantly on oral rather than pharyngeal musculature. Validity (n = 117) was widely reported, primarily via known-group validity or hypothesis testing. Fewer studies examined reliability (n = 20) and responsiveness (n = 25); however, where reported, results indicated excellent intra- and inter-rater reliability and responsiveness to therapeutic interventions. A diverse range of single-item measures were identified across included measurement techniques. Measurement properties were sparsely reported. Future research should focus on rigorous measurement instrument design and standardisation to comprehensively evaluate the underlying mechanisms of dysphagia.