Date Published: January 23, 2019
Publisher: Public Library of Science
Author(s): Kumi Igarashi, Takeshi Kikutani, Fumiyo Tamura, Michelle Ciucci.
This study was carried out to determine the prevalence of suspected dysphagia and its features in both independent and dependent older people living at home.
The 10-Item Eating Assessment Tool (EAT-10) questionnaire was sent to 1,000 independent older people and 2,000 dependent older people living at home in a municipal district of Tokyo, Japan. The participants were selected by stratified randomization according to age and care level. We set the cut-off value of EAT-10 at a score of ≥3. The percentage of participants with an EAT-10 score ≥3 was defined as the prevalence of suspected dysphagia. The chi-square test was used for analyzing prevalence in each group. Analysis of the distribution of EAT-10 scores, and comparisons among items, age groups, and care levels to identify symptom features were performed using the Kruskal-Wallis test and Mann-Whitney U test.
Valid responses were received from 510 independent older people aged 65 years or older (mean age 75.0 ± 7.2) and 886 dependent older people (mean age 82.3 ± 6.7). The prevalences of suspected dysphagia were 25.1% and 53.8%, respectively, and showed significant increases with advancing age and care level. In both groups, many older people assigned high scores to the item about coughing, whereas individuals requiring high-level care assigned higher scores to the items about not only coughing but also swallowing of solids and quality of life.
In independent people, approximately one in four individuals showed suspected dysphagia and coughing was the most perceivable symptom. In dependent people, approximately one in two individuals showed suspected dysphagia and their specifically perceivable symptoms were coughing, difficulties in swallowing solids and psychological burden.
Dysphagia causes dehydration and malnutrition and increases the risk of aspiration pneumonia and mortality. It also impacts quality of life (QOL)  and social well-being  for the older people. In 2015, the mortality rate from pneumonia was approximately 9.4% , and aspiration pneumonia accounted for a majority of older people pneumonia cases in Japan . In order to prevent aspiration pneumonia, it is necessary to establish a social system that enables early detection of and intervention for dysphagia. Thus, it is important to determine the prevalence and features of dysphagia.
This survey was carried out as part of a regional survey on eating/swallowing conducted by a local government. The numbers of independent and dependent older people aged 60 years or older residing in a city in the Tama area of Tokyo, Japan were 47,000 and 7500, respectively. Sample size was calculated to ensure a power = 95% (type II error), and the level of significance at ≤5% (type I error). The effect size was assumed to be medium. The response rate for another survey conducted in this city was 43.54% (data not shown). Therefore, we planned to send the EAT-10 to more than 701 older people in this study. G*Power 184.108.40.206 Statistical Power Analyses for Windows was used to estimate the sample size .
The number of participants and effective response rates in each group are shown in Tables 2 and 3. The effective response from the participants was sufficient enough for analysis.
In this study, the prevalences of suspected dysphagia in independent and dependent older people were 25. 1 and 53.8%, respectively, demonstrating a substantial proportion of individuals in both groups to have suspected dysphagia. We found interesting features: the distribution of scores for the questionnaire items differed with increase in age and care level, and older people became aware of more subjective symptoms with increase in age and care level. Coughing was found to be the easiest item to notice, and people with higher care levels were more likely to experience difficulties in swallowing solids and to experience a mental burden. These results could contribute to promotion of eating/swallowing support in the community.