Objectives: The objective of this study was to assess the prevalence of subjective daytime sleepiness among the community-dwelling elderly population in Japan using the Japanese version of the Epworth Sleepiness Scale (JESS) and to investigate the correlates of excessive daytime sleepiness (EDS).
Methods: Subjects aged 65 years or older, born between April and September, living independently, who resided in 1 district of Tokyo, Japan, were recruited. A total of 3195 subjects meeting the inclusion criteria were mailed a questionnaire that inquired about the JESS, socio-demographic factors, and health-related factors. Of the 2034 elderly individuals who responded to the survey (response rate, 63.7%), 1494 subjects (652 men, 842 women) who completely answered the questionnaire were included in the study (valid response rate, 46.8%).
Results: The mean (+/- standard deviation) JESS score was 5.0 +/- 3.8 (men 5.6 +/- 4.1, women 4.4 +/- 3.4, P <0.01). The prevalence of EDS (a cut-off score>10) was 8.8% (men 12.7%, women 5.7%, P< 0.01). The male gender, being employed, having poor mental health and well-being, having lowered activity of daily living (ADL), or having subjective memory impairment were significantly associated with EDS. In the gender-specific models, low social network and subjective memory impairment in men, whereas obesity and lowered ADL in women, were significantly associated with EDS.
Conclusion: EDS was more frequently observed in men than in women among the community-dwelling elderly population in Japan. A substantial gender difference was found in correlates of EDS. This finding is useful in the clinical management of patients who complain of daytime sleepiness; moreover, it is useful for the management of public health.