Impact of daytime sleepiness on rehabilitation outcome in the elderly

Daytime sleepiness (DS) is associated with poor health, impaired physical functioning, as well as somatic and psychiatric morbidity. The impact of DS on functional outcome in the elderly is unknown. We investigated whether observed daytime sleepiness in geriatric patients with moderate to severe functional impairment was associated with functional clinical outcomes. We addressed the issue by determining the impact of observed daytime sleepiness, by means of the Essener Questionnaire of Age and Sleepiness (EQAS), on improvement in functional status - measured by the Barthel ADL Index - among disabled geriatric in-patients. We included 129 patients, 28 (22%) were male and 101 (78%) were female. Sleepiness according to EQAS scale was absent in 27 (21%) patients, mild in 71 (55%) patients and moderate to severe in 31 (24%) patients. The three patient groups did not differ in the Barthel ADL Index (BI) on admission or co-morbid conditions. Geriatric treatment was comparable across groups. Improvement in the BI of at least 1 standard deviation (SD) occurred in 23/27 (85%) of subjects without sleepiness, in 53/71 (75%) of subjects with mild to moderate sleepiness and in 15/31 (44%) of subject with severe sleepiness (p < 0.01). BI increased at least 2 SD in 20/27 (74%), 38/71 (54%) and 11/31 (35%) individuals, respectively (p < 0.02). We conclude that the daytime sleepiness predicts a poorer functional recovery rate in older patients during geriatric in-hospital rehabilitation. Furthermore, we found a significant association and a dose response relationship between severity of daytime sleepiness and improvement in Barthel ADL Index.