Abstract
We performed a systematic review evaluating evidence regarding whether/which 24-h sleep-wake characteristics (e.g. sleep, activity levels, and 24-h rhythms) related to worse BPSDs. We searched PubMed for cross-sectional observational studies of people with dementia examining relationships between actigraphy-measured sleep/wake factors and BPSDs (search completed June 2024). We used the JBI checklists to assess the risk of bias and summarize results within subcategories of sleep/wake (sleep, activity level, and rhythm) and BPSD (composite, agitation, apathy, and mood/affect) dimensions. Thirteen articles met inclusion criteria. Measures of inactivity were most frequently examined and correlated with: (a) greater apathy (6/6 studies); (b) worse depression (only in bivariate analyses in 1 study); (c) more agitation (2/3 studies); and (d) higher composite BPSD scores (1/2 studies). All six studies measuring sleep duration failed to identify associations with BPSDs. Studies examining sleep continuity measures generally found associations, i.e. with a BPSD composite (1 study), agitation (1 study), apathy (1/2 studies), and mood (only in bivariate analyses in 1 study). Studies examining rhythm variables found associations with mood (1 study), mixed evidence for associations with apathy (1 study), and no evidence for association with a BPSD composite (1 study). Actigraphy measures of inactivity are associated with apathy in people with dementia. Due to relatively low numbers of articles, future studies are needed to confirm if inactivity, sleep continuity issues, rhythm disruption, and timing independently relate to BPSDs, and if changes in objective sleep/wake measures, e.g. increase in activity following intervention, signal/mediate improvements in BPSDs.