More Daytime Sleeping Predicts Less Functional Recovery Among Older People Undergoing Inpatient Post-Acute Rehabilitation

STUDY OBJECTIVES: To study the association between sleep/wake patterns among older adults during inpatient post-acute rehabilitation and their immediate and long-term functional recovery DESIGN: Prospective, observational cohort study. SETTING: Two inpatient post-acute rehabilitation sites (one community and one Veterans Administration). PARTICIPANTS: Older patients (aged > or = 65 years, N = 245) admitted for inpatient post-acute rehabilitation. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Based on 7-day wrist actigraphy during the rehabilitation stay, mean nighttime percent sleep was only 52.2% and mean daytime percent sleep was 15.8% (16.3% based on structured behavioral observations). Using the Pittsburgh Sleep Quality Index (PSQI), participants reported their sleep was worse during rehabilitation compared to their premorbid sleep. Functional recovery between admission and discharge from rehabilitation (measured by the motor component of the Functional Independence Measure) was not significantly associated with reported sleep quality (PSQI scores) or actigraphically measured nighttime sleep. However, more daytime percent sleep (estimated by actigraphy and observations) during the rehabilitation stay was associated with less functional recovery from admission to discharge, even after adjusting for other significant predictors of functional recovery (mental status, hours of rehabilitation therapy received, rehospitalization, and reason for admission; adjusted R2= 0.267, P < 0.0001). More daytime sleeping during rehabilitation remained a significant predictor of less functional recovery in adjusted analyses at 3-month follow-up. CONCLUSIONS: Sleep disturbance is common among older people undergoing inpatient post-acute rehabilitation. These data suggest that more daytime sleeping during the rehabilitation stay is associated with less functional recovery for up to three months after admission for rehabilitation.