Limits of the Epworth Sleepiness Scale in older adults

Excessive daytime sleepiness (EDS) in older adults is associated with obstructive sleep apnea, falls, reduced quality of life, and mortality. The Epworth Sleepiness Scale (ESS) is widely used to assess sleepiness. However, EDS assessment with the ESS may not be accurate in older adults. We aimed to (1) describe the responsiveness of nondemented older subjects to the ESS and (2) compare the self-report ESS scores to those of close relatives (CR) proxy and identify factors influencing any discrepancies between them. This is a cross-sectional observational study including 104 independently living nondemented older subjects with daytime sleepiness complaints and 104 nondemented CRs. Cognitive tests (Mini-Mental State Examination) and the ESS were completed separately by subjects and CRs to assess the subject's daytime sleepiness. Almost 60 % of subjects and CRs were not able to answer at least one question on the ESS. Despite the fact that all subjects complained of EDS, only 24 % of them had an abnormal ESS score (> 10). Subjects rated their sleepiness lower (7.10 +/- 4.31) than their CR proxy did (9.70 +/- 5.14) (p < 0.0001). In multivariate analysis, an increase in age and a decrease in cognitive status of the subjects appeared related to the difference in ESS between subject and CR. The majority of older adults were not able to answer all of the ESS items. The ESS may underestimate sleepiness severity in older subjects. Despite EDS complaints in all subjects, only one quarter of them had a pathological ESS score.