Effectiveness of Bright and Other Light Therapy (BOLT) in improving sleep problems among dementia patients: A systematic review and meta-analysis

Abstract

Background: Sleep disturbances in dementia patients are commonplace. Light therapy is a promising non-pharmacological approach to reduce sleep disturbances by helping to regulate the sleep/wake cycle. However, the literature remains inconclusive, highlighting the need for a comprehensive systematic review to draw more definitive conclusions. Objectives: This review aims to synthesize the best available evidence regarding the effectiveness of light therapy in reducing sleep problems of dementia patients. Methods: PubMed, Embase, Scopus, CINAHL, The Cochrane Library, ALOIS, PsycInfo, Web of Science, ALOIS, ProQuest, OpenGrey, trial registries and sleep journals were searched with no year limitations. All relevant published or unpublished randomised controlled trials (RCTs) with light therapy, sleep outcomes and patients with dementia of all types and severity were included. Cochrane’s Risk of Bias Tool and GRADE were used to assess the quality of the studies by two independent reviewers. Data extraction was also performed by two independent reviewers. RevMan was used to perform meta-analysis with I ² determining heterogeneity. Results: 6536 records were identified with 14 RCTs involving 751 dementia participants. Meta-analysis demonstrated statistical significance for a small reduction in nighttime awakenings ( p =0.002) and negligible effects size in relative amplitude ( p =0.005). Subgroup analysis revealed afternoon/evening light of more than 1,000 lux over a period greater than six weeks may demonstrate greater effectiveness over the other respective subgroups. Conclusion: Light therapy can improve dementia patients' sleep quality by reducing nighttime awakenings, however more research is needed to determine the most effective combination of light therapy parameters and dementia severity. Implications: Long-term care facilities and homes can use light therapy to improve dementia patients' sleep quality, reduce caregiver burden and improve patient’s quality of life.