Performance of Japanese community-dwelling older adults in the 100-mL water swallowing test

Abstract

Background: Although the 100-mL water swallowing test (WST) is used to measure swallowing capacity (SC), volume per swallow (VS), time per swallow (TS), and the presence/absence of choking signs, the performance of each indicator is not clearly understood. The purpose of this study was to identify the relationship between performance in each indicator in the 100-mL WST and risk factors for dysphagia in community-dwelling older adults. Methods: Participants included 304 Japanese community-dwelling older adults aged ≥65 years. We investigated participant characteristics including age, sex, body mass index (BMI), medical history, number of prescribed medications, laryngeal function (maximum phonation time [MPT]), subjective dysphagia (the 10-item eating assessment tool [EAT-10]), and all indicators of the 100-mL WST. We compared each of the four indicators in the 100-mL WST and investigated their relationship with potential risk factors for dysphagia. Results: Multivariate analyses showed that age, BMI, MPT, and EAT-10 were independently associated with SC. Age, sex, BMI, and EAT-10 were independently associated with VS. BMI, MPT, and EAT-10 were independently associated with TS. Men were more likely to have choking signs in the 100-mL WST than women. Conclusions: These findings indicated that all of three quantitative indicators in the 100-mL WST may predict the risk of sarcopenic dysphagia. Moreover, the presence of choking signs in men suggested the risk of aspiration. We propose that SC and choking signs in the 100-mL WST could be a simple and useful dysphagia assessment tool for community-dwelling older people.