Factors associated with concordance and variability of sleep quality in persons with Alzheimer's disease and their caregivers.

STUDY OBJECTIVES To describe the day-to-day variation in sleep characteristics and the concordance between nighttime sleep of persons with Alzheimer's disease (AD) and their family caregivers. PARTICIPANTS N = 44 community-dwelling older adults with probable or possible AD and their co-residing family caregivers. DESIGN Participants wore an Actillume (Ambulatory Monitoring, Inc) for one week and completed an assessment battery to evaluate patient and caregiver mood, physical function, medication use, caregiver behavior management style, and patient cognitive status. MEASUREMENTS AND RESULTS Actigraphically derived sleep measures included bedtime, rising time, total time in bed, total sleep time, number of awakenings, total wake time, and sleep percent (efficiency). For each sleep parameter, total variance was determined for between-subject variance and within-subject variance from day-to-day. Sleep concordance was examined using multinomial logistic regression to compare trichotomous patient-caregiver combinations of good and bad sleepers. For both patients and caregivers, between-subject daily variability accounted for more of the variance in sleep than within-subject variability. Patient depression and caregiver management style were significant predictors both for concordant poor sleep (both patient and caregiver with sleep efficiency < or =85%) and patient-caregiver sleep discordance. CONCLUSIONS This study provides data that sleep disturbances for persons with AD and their family caregivers vary considerably night to night, and that poor sleep in one member of the caregiving dyad is not necessarily linked to disturbed sleep in the other. Understanding the complex interrelationship of sleep in AD patients and caregivers is an important first step towards the development of individualized and effective treatment strategies.