Functional outcomes of excessive daytime sleepiness in older adults

OBJECTIVES: To describe the effect of self-reported excessive daytime sleepiness (EDS) on functional outcomes. DESIGN: Case-control study designed to examine differences in functional status between cases (with daytime sleepiness) and controls (no daytime sleepiness) with regard to demographic factors, general health, sleep history, and medications. SETTING: Retirement communities in southeastern Pennsylvania, Delaware, and New Jersey. PARTICIPANTS: Seventy-six nondepressed, nondemented adults, aged 65 and older, were cases (had daytime sleepiness) and 38 were controls (had no daytime sleepiness). MEASUREMENTS: Standardized questionnaires to assess disease-specific functional status (Functional Outcomes of Sleepiness Questionnaire (FOSQ) and Epworth Sleepiness Scale (ESS)), depression (Geriatric Depression Scale-Short Form and the Center for Epidemiologic Studies-Depression Scale), dementia (Short Blessed Test), demographic factors, current medical history, and sleep complaints. RESULTS: There was a significant difference in functional status between sleepy cases and nonsleepy controls. Sleepiness had a moderate to large negative effect (effect size range from 0.59 to 0.83, P < .005) on the following functional domains of the FOSQ: social outcome, general productivity, vigilance, activity level, and global assessment of functional status. Correlation between ESS and FOSQ subscales were -0.31 to -0.67, P < .05. Examination of cases with daytime sleepiness revealed increased functional impairment in individuals with more than three medical conditions or those taking more than four medications (P < .001 and P = .03, respectively). CONCLUSION: Daytime sleepiness is associated with functional impairments in a broad range of activities. The decrease in daily functioning noted in the sleepy subjects has implications for deconditioning and related comorbidity. These findings suggest that exploration of daytime sleepiness should be part of the ongoing assessment of the elderly, particularly those with multiple medical conditions.