Objectives: Discrepancy between self-report- and actigraphy-measured sleep, often considered an artifact of measurement error, has been well documented among insomnia patients. Sleep problems are common among older adults, and this discrepancy may represent meaningful sleep-related phenomenon, which could have clinical and research significance.
Method: Sleep discrepancy was examined in 4 groups of older adults (N = 152, mean age = 71.93 years) based on sleep complaint versus no complaint and presence versus absence of insomnia symptoms. Participants completed the Beck Depression Inventory-second edition (BDI-II) and 14 nights of sleep diaries and actigraphy.
Results: Controlling for covariates, group differences were found in the duration and frequency of discrepancy in sleep onset latency (SOLd) and wake after sleep onset (WASOd). Those with insomnia symptoms and complaints reported greater duration and frequency of WASOd than the other 3 groups. Quantities of SOLd and WASOd were related to BDI-II score and group status, indicating that sleep discrepancy has meaningful clinical correlates.
Discussion: Discrepancy occurred across all groups but was pronounced among the group with both insomnia symptoms and complaints. This discrepancy may provide a means of quantifying and conceptualizing the transition from wake to sleep among older adults, particularly those with sleeping problems.
Keywords: Depression; Insomnia; Older adults; Sleep; Sleep discrepancy.