The Test of Mastication and Swallowing Solids and the Timed Water Swallow Test: Reliability, associations, age and gender effects, and normative data.

Abstract

Quantitative measures can increase precision in describing swallowing function, improve interrater and test-retest reliability, and advance clinical decision-making. The Test of Mastication and Swallowing Solids (TOMASS) and the Timed Water Swallow Test (TWST) are functional tests for swallowing that provide quantitative results. To explore the relationship between TOMASS and TWST; evaluate test-retest and interrater reliability; explore age and gender effects; and gather normative data. Healthy community dwelling participants (n = 298, ≥ 20 years old) were recruited. Of those, 126 were included in the reliability study. Participants completed the TWST and TOMASS. Associations between TWST and TOMASS measures were found using Pearson's correlation coefficient. Age was positively associated with an increase in the number of bites (n = 292, r = 0.15, p = 0.009), masticatory cycles (n = 291, r = 0.33, p < 0.0001) and duration (n = 292, r = 0.32, p < 0.0001) for the TOMASS. For the TWST, age was positively associated with an increase in duration (n = 296, r = 0.23, p < 0.0001), and negatively associated with volume (n = 296, r = -0.205, p < 0.0001), and swallowing capacity (n = 296, r = -0.24, p < 0.0001). Females required more bites, masticatory cycles, swallows and longer time than males in TOMASS. In TWST, females required more swallows, longer time, and had lower volume per swallow and reduced swallowing capacity than males. Intraclass correlation coefficient (ICC) revealed good test-retest reliability and moderate to excellent interrater reliability. This study provides support for the validity of the TOMASS and TWST. Reduced efficiency in one of the tests might indicate a need to evaluate performance in the other. Extended chewing time and increased number of masticatory cycles might be compensatory behaviours for reduced oral processing abilities that are motor, sensory and/or mechanical. The TOMASS and TWST are functional tests of swallowing that provide quantitative results. They are easy to incorporate as part of the clinical evaluation of swallowing due to low cost and quick administration. Age and gender effects were found for the TWST and TOMASS, but they were only tested on relative measures rather than absolute measures. Different types of crackers used for TOMASS led to differences in performance and in normative values. What is already known on the subject Associations between performance during TWST and TOMASS were found: time, number of swallows and time per swallow were correlated, meaning that need for more time and more swallows is reflected in both drinking and chewing. The study provides further support for age and gender effects in TWST and TOMASS, on both relative and also on absolute measures, which were not investigated previously. Longer durations in TOMASS and TWST with an increase in age, are likely to be the result of compensatory behaviours to allow safe swallowing. Normative data for a country-specific cracker are presented (Israel). What are the potential or actual clinical implications of this work? Reduced efficiency in one of the tests might indicate a need to evaluate performance in the other. Establishing country specific norms for commonly available crackers is necessary, since crackers size and ingredients, such as fat content and moisture, influence chewing and swallowing. There is a balancing act between safety and efficiency in older adults' swallowing behaviour. Reducing pace in eating and drinking probably supports safer swallowing.