Effectiveness of a Virtual Reality Open-Air Bath Program in Reducing Loneliness and Improving Brain Function for Dementia Prevention in Older Adults: A Prospective Randomized Crossover Study Protocol

Background: Older adults often face loneliness due to chronic illness or loss of close ones, a situation worsened by COVID-19. Increased loneliness heightens the risk of diseases, especially dementia, necessitating urgent action. This study aims to assess the impact of a virtual reality (VR)-based open-air bath program on depression and loneliness in elderly individuals with Subjective Cognitive Decline/Mild Cognitive Impairment (SCD/MCI) attending our Dementia Medical Centre and evaluate the feasibility (participant recruitment and adherence) and measuring program enjoyment and satisfaction. Methods The study design is a crossover trial with a 1:1 ratio wherein 12 participants will be randomly assigned to Groups 1 and 2, with Group 2 serving as a waitlist control, and the VR program will be conducted six times (monthly). Group 1 will participate from the program's commencement and continue for 6 months, followed by an observation period from months 7 to 12. Group 2 will participate from months 7 to 12, with an observation period from months 1 to 6. Cognitive tests, psychiatric assessments, and the UCLA loneliness scale will be conducted before the study, at 6 months, and at 12 months. Results will be analyzed using repeated measures ANOVA. Head MRI and SPECT scans will be performed pre- and post-VR program to evaluate changes and effects on brain regions. Recruitment began in September 2023, and data collection is expected to be completed by March 2025. Complete study results will be published by September 2025. Discussion The study examines the preliminary effects of VR on loneliness in predementia seniors through open-air bath simulations. Virtual reality experiences could benefit this population, particularly those with limited outdoor activities. Quantifying VR's impact will aid in determining the size for a larger clinical trial. Qualitative results will inform participation mechanisms and guide the implementation and design of future trials. Trial registration : The protocol and informed consent were approved by the Ethical Review Board of Kyoto Prefectural University of Medicine on October 31, 2023 (ERB-C-2978). The study has been registered in the University Hospital Medical Information Network (UMIN) on November 1, 2023 (Trial Registration Number: 000052667).