Accelerometer-Derived Rest–Activity Rhythms and Sleep Disturbance in Older Adults: A Three-Wave Longitudinal Study

Purpose: To examine associations between accelerometer-derived rest–activity indicators and sleep disturbance among older adults.Methods: This analysis included 1,373 person-wave observations from 569 National Health and Aging Trends Study participants. Multilevel models separated within-person and between-person components of the least active five-hour period (L5), coefficient of variation, and behavioral fragmentation. Relative amplitude (RA) was included at the between-person level in the primary model and examined separately in sensitivity analyses.Results: In primary analyses, no rest–activity indicator was associated with sleep disturbance, including when sleep medication use was excluded; within-person estimates were small (95% CI bounds within ±0.031). Weak between-person associations for L5 and RA emerged only in exploratory, model-dependent analyses. Pain, depressive symptoms, chronic disease burden, and educational attainment were associated with sleep disturbance.Conclusion: Rest–activity indicators showed no clear association with self-reported sleep disturbance, and small between-person estimates were model-dependent. Health-related and socioeconomic factors warrant attention in population-based sleep research.