Assessment of sleep and circadian rhythm disorders in the very old: The newcastle 85+ cohort study

Abstract

Objectives: To examine the association between subjective and objective measures of sleep and wake and other health parameters in a cohort of the very old. Design: A population-based cohort study. Setting: Primary care, North East England. Participants: four hundred and twenty-one men and women, aged 87-89, recruited to the Newcastle 85+ Study cohort. Methods: Sleep questionnaires were administered and sleep-wake patterns were assessed over 5-7 days with a novel wrist triaxial accelerometer. Associations between sleep measures and various health parameters, including mortality at 24 months, were examined. Results: Only 16% of participants perceived their sleep as severely disturbed as assessed with questionnaire responses.Wrist accelerometry showed marked variation between normal and abnormal sleep-wake cycles that did not correlate with the participants' perception of sleep. Impaired sleep-wake cycles were significantly associated with cognitive impairment, disability, depression, increased falls, bodymass index and arthritis but not with any other specific disease markers and with decreased survival. Conclusions: Commonly used sleep questionnaires do not differentiate well between those with objectively determined disturbance of sleep-wake cycles and those with normal cycles. Abnormal sleep-wake patterns are associated with institutionalisation, cognitive impairment, disability, depression and arthritis but not with other diseases; there is also an association with reduced survival. © The Author 2013. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.