Swallowing assessment in patients with dysphagia: Validity and reliability of a pocket-sized ultrasound system.

BACKGROUND: The use of ultrasound as an adjunct to clinical swallowing evaluation provides quantitative physiological and morphological data. As a low-risk procedure, ultrasound imaging can be performed outside of a medical setting. This is particularly important for patients living in rural areas with restricted access to a hospital. Technical advances have produced pocket-sized ultrasound technology that is more affordable, and therefore within the fiscal reach of most allied health services. AIMS: To explore the validity and reliability of pocket-sized ultrasound technology in dysphagia assessment. METHODS & PROCEDURES: Data were acquired from 43 patients with dysphagia using the Clarius ultrasound device. Ultrasound and videofluoroscopic measures of hyoid and laryngeal displacement during liquid and puree swallowing were collected concurrently to quantify correlation and agreement between identical measures derived from the two instruments. Reliability of ultrasound was assessed for measures of hyoid and laryngeal displacement, tongue thickness, and size of the submental muscles in eight patients. Reliability was evaluated for the entire process of data acquisition including scanning and online measurement using an iPad in a clinical setting and for offline measurement on a computer screen to explore environmental influences on reliability. OUTCOMES & RESULTS: Results revealed poor correlation between the measures of interest across instruments. Reliability of the entire process of data acquisition in a clinical setting was insufficient while reliability was more promising for offline measurements. CONCLUSIONS & IMPLICATIONS: The clinical use of pocket-sized ultrasound devices, such as the Clarius system, for swallowing evaluation is not indicated at this time. Enhanced validity and reliability of the entire process of data acquisition are needed prior to clinical translation of such technology. WHAT THIS PAPER ADDS: What is already known on the subject The use of ultrasound allows for radiation-free, non-invasive swallowing assessment. Some data suggest that ultrasound is valid and reliable in the evaluation of swallowing using standard-sized equipment. Insufficient validity and reliability have been reported for pocket-sized ultrasound technology in the assessment of healthy swallowing. What this paper adds to existing knowledge This research is the first to provide validity and reliability data of the pocket-sized Clarius technology in the evaluation of swallowing in patients with dysphagia. Insufficient validity and reliability of online data acquisition in a clinical environment were found. Reliability for offline measurement was more promising. What are the potential or actual clinical implications of this work? The clinical use of pocket-sized ultrasound devices, such as the Clarius system, for swallowing assessment is not indicated at this time.

Ultrasound: Reliability of a Pocket-Sized System in the Assessment of Swallowing.

Purpose Ultrasound imaging offers a noninvasive adjunct to clinical swallowing assessment. Published reliability of sophisticated ultrasound systems is promising; however, no data exist for reliability using more affordable, pocket-sized devices. This study explored intrarater, interrater, and test-retest reliability of swallowing measures acquired with pocket-sized ultrasound technology. Method Five participants collected measures of swallowing from 20 healthy individuals using the Clarius ultrasound. Hyoid excursion and thyrohyoid approximation were derived during saliva, liquid, and puree swallowing. The cross-sectional area of the floor of mouth muscles and tongue thickness were obtained at rest. Measures were collected at two occasions minimum 11 days apart. Reliability was assessed for the entire process of data acquisition including scanning and online measurement, and for offline measurement of saved images. Results For most measures, reliability was poor (ICC [intraclass correlation coefficient] < .50) to moderate (ICC = .50-.75) for the entire process of data acquisition and poor to good (ICC > .75) when measuring saved images. Conclusion Further work is needed to elucidate whether our study findings apply to the Clarius system only or the data suggest a general limitation of pocket-sized ultrasound technology.

The Test of Masticating and Swallowing Solids (TOMASS): reliability, validity and international normative data.

BACKGROUND: Clinical swallowing assessment is largely limited to qualitative assessment of behavioural observations. There are limited quantitative data that can be compared with a healthy population for identification of impairment. The Test of Masticating and Swallowing Solids (TOMASS) was developed as a quantitative assessment of solid bolus ingestion. AIMS: This research programme investigated test development indices and established normative data for the TOMASS to support translation to clinical dysphagia assessment. METHODS & PROCEDURES: A total of 228 healthy adults (ages 20-80+ years) stratified by age and sex participated in one or more of four consecutive studies evaluating test-retest and interrater reliability and validity to instrumental assessment. For each study the test required participants to ingest a commercially available cracker with instructions to 'eat this as quickly as is comfortably possible'. Further averaged measures were derived including the number of masticatory cycles and swallows per bite, and time per bite, masticatory cycle and swallow. Initial analyses identified significant differences on salient measures between two commercially available crackers that are nearly identical in shape, size and ingredients, suggesting the need for separate normative samples for specific regional products. Additional analyses on a single cracker identified that the TOMASS was sensitive at detecting changes in performance based on age and sex. Test-retest reliability across days and interrater reliability between clinicians was high, as was validation of observational measures to instrumental correlates of the same behaviours. Therefore, normative data are provided for the TOMASS from a minimum of 80 healthy controls, stratified by age and sex, for each of seven commercially available crackers from broad regions worldwide. OUTCOMES & RESULTS: Analyses on a single cracker identified Arnott's Salada, and that TOMASS measures were sensitive for detecting changes in performance based on age and sex. Interrater and test-retest reliability across days were high, as was validation of observational measures to instrumental correlates of the same behaviours. Significant differences were identified between two commercially available crackers, nearly identical in shape, size and ingredients, thus normative samples for specific regional products were required. Normative data were then acquired for the TOMASS from a minimum of 80 healthy controls, stratified by age and sex, for each of seven commercially available crackers from broad regions worldwide. CONCLUSIONS & IMPLICATIONS: The TOMASS is presented as a valid, reliable and broadly normed clinical assessment of solid bolus ingestion. Clinical application may help identify dysphagic patients at bedside and provide a non-invasive, but sensitive, measure of functional change in swallowing.