Introduction: The Timed-Water Swallow Test (TWST) (Hughes & Wiles, 1996) and Test of Masticating and Swallowing Solids (ToMaSS) (Huckabee et al., 2018) are quantitative assessments used as adjuncts to the clinical swallowing evaluation (CSE) to assess the efficiency of liquid and solid ingestion. The ToMaSSApp™ was recently developed as an alternative to the manual, paper and pen, recording method for the ToMaSS that can also be used to administer the TWST. Previously, small sample sizes were used to establish normative data for each recording method. This research established normative data from a large sample of healthy adults for the TWST and ToMaSS using the ToMaSSApp™. Normative data were further explored for age and sex effects of ToMaSS and TWST measures.

Methods and Procedures: Healthy adults (aged 20 to 80+ years) were recruited from the general public. Participants were required to complete the TWST followed by the ToMaSS. The TWST data were based on ingestion of bottled still water or tap water; ToMaSS data were based on ingestion of the Arnott’s Salada™ cracker. Using the same methods as previously reported by Hughes and Wiles (1996) and Huckabee et al., (2018), participants were instructed to drink the water or eat the cracker ‘as quickly as is comfortably possible’. Participants were observed from the side, and raw TWST (number of swallows and total time) and ToMaSS (number of bites, masticatory cycles, swallows, and total time) measures were recorded using the ToMaSSApp™. Age and sex effects were explored using permutation ANOVA to calculate interaction effect. From this, estimated median, bootstrapped 95% CI and bootstrapped p-values were calculated for age and sex comparisons. Normative data, stratified by age and sex, were represented by medians, first and third quartiles, and inter-quartile ranges.

Results and Outcomes: A total of 437 healthy participants (aged 20 to 80+ years), stratified by age and sex, participated in the study. No significant differences were found in any TWST and ToMaSS measure in the younger age groups (i.e. 20-39 and 40-59). Significant differences were found for the older age groups (i.e. 60-79 and 80-99), except for time per swallow in males for the TWST and the number of swallows for the ToMaSS in both males and females. Significant differences and increased variability in the older age groups were found particularly in females. These findings indicated the importance of using a large sample size, which increases statistical power and is less influenced by outliers and Type I error. It is also important for understanding variability in swallowing measures in older adults. These normative data are more representation of the healthy adult population, and can be used clinically when administering either the manual, paper and pen, recording method or the ToMaSSApp™.