Predictive Factors for Swallowing Function Decline in Older Adults With Alzheimer's Disease: A 1-Year Longitudinal Study

Background: By 2060, the global burden of dementia, particularly Alzheimer's disease (AD), is expected to increase significantly, necessitating effective palliative care strategies. Dysphagia, a common condition among people with dementia, leads to malnutrition, aspiration pneumonia, and a reduced quality of life.

Objective: This study aimed to identify oral health management factors that could predict a decline in swallowing function in older adults with AD.

Methods: Data from the Akita-Omorimachi study, which included 63 adults diagnosed with AD, were analysed. Swallowing function was assessed using the modified water-swallowing test (MWST) at baseline and after 1 year.

Results: The results indicated that 25.4% of participants exhibited a decline in swallowing function, as indicated by a decrease from the highest MWST score of 5 at baseline to a lower score at follow-up. Poisson regression analysis revealed that refusal of oral care (incidence rate ratio (IRR): 7.28), tongue coating (IRR: 4.21), and unclear articulation of /ka/ (IRR: 5.79) were significant predictors of swallowing function decline. The participants with these indicators had a higher risk of developing dysphagia.

Conclusions: These findings suggest that factors related to specific oral health problems may predict poor swallowing function in older adults with AD. Moreover, implementing targeted oral care interventions, including person-centered care and regular tongue cleaning, may improve the outcomes in this vulnerable population. Despite the limitations of this study, including a small sample size, the results underscore the importance of comprehensive oral health management in preventing dysphagia-related complications.