Supplementary Material for: Real-World Multimodal Day-Care Intervention for Mild Cognitive Impairment with Lewy Bodies: A Prospective 3-Year Comparative Cognitive Trajectory Study

Background: Mild cognitive impairment with Lewy bodies (MCI-LB) is generally associated with more rapid cognitive decline than mild cognitive impairment due to Alzheimer’s disease (MCI-AD). However, evidence regarding the potential cognitive trajectories of individuals with MCI-LB participating in structured non-pharmacological multimodal programs remains limited. Objective: To preliminarily examine cognitive changes over time among individuals with MCI-LB and MCI-AD undergoing a multimodal intervention. Methods: Conducted at the University of Tsukuba Hospital between April 2013 and February 2020, this prospective study enrolled 74 participants (MCI-LB: 14; MCI-AD: 60) in the Cognitive Improvement Day-Care (CIDC) program. The CIDC was a multimodal intervention offering structured sessions including physical exercise, cognitive training, music therapy, and art-based activities. Participants attended the program, mostly once a week, and underwent annual cognitive assessments for up to three years using the Mini-Mental State Examination (MMSE-J). Linear mixed-effects models were used to analyze longitudinal changes in MMSE-J scores. Results: The overall annual cognitive decline was –0.36 points/year (95% CI: –0.63, 0.10). The annual decline was –0.44 points/year (95% CI: –0.95, 0.06) for the MCI-LB group and –0.34 points/year (95% CI: –0.64, -0.03) for the MCI-AD group. No significant group-by-time interaction was observed over the three-year follow-up (P = 0.97). Conclusions: These findings suggest that individuals with MCI-LB exhibited longitudinal cognitive trajectories under a structured multimodal intervention that were comparable to those observed in individuals with MCI-AD, at least as assessed by the MMSE-J. Future studies with larger samples and more detailed cognitive assessments are needed to clarify potential subtype-specific responses.