Prevalence, dimensions, and correlates of excessive daytime sleepiness in community-dwelling older adults: the Yilan study, Taiwan

Abstract

Background Daytime sleepiness is an important health problem. However, the dimensionality of the Epworth Sleepiness Scale (ESS) in older adults remains unclear. This study aimed to determine the prevalence of ESS-defined excessive daytime sleepiness in older adults. Furthermore, the dimensionality of ESS and its respective correlates were also compared. Materials and methods This is a community-based survey in which community-dwelling older adults aged ≥ 65 years participated. Excessive daytime sleepiness was assessed using the ESS and was defined as an ESS score of > 10. Exploratory factor analysis was performed to identify the ESS factors. Multiple logistic regression analysis was used to examine the independent correlates of the ESS-defined and factor-specific correlates of excessive daytime sleepiness. Results In total, 3978 older adults participated in this study. The mean age was 76.6 ± 6.7 years, with 53.8% ≥ 75 years, and 57.1% were female. The prevalence of ESS-defined excessive daytime sleepiness was 16.0%. An exploratory factor analysis revealed two factors in the ESS, which were designated as ‘passive’ and ‘active’ according to the soporific levels of ESS items loaded in each factor. Multiple logistic regression showed that male, illiteracy, depression, disability, short sleep duration and no exposure to hypnotics were risk indicators for ESS-defined excessive daytime sleepiness. However, the correlates for passive and active factor-defined excessive daytime sleepiness differ in pattern, especially in variables related to education, exercise, mental health, and sleep. Conclusions The prevalence of ESS-defined excessive daytime sleepiness is high, and its correlates vary among older adults. This study also suggests a dual ESS structure in community-dwelling older adults.