Feasibility and effectiveness of a handbook-based multidomain lifestyle intervention for older adults with mild cognitive impairment: A quasi-experimental design with propensity score matching

Background The increasing prevalence of dementia highlights the urgent need for the social implementation of nonpharmacological interventions for its prevention. To address professional staff shortage challenges, we developed the MCI Handbook , a structured resource designed to guide non-professionals in promoting dementia prevention. Objective We aimed to evaluate the feasibility and effectiveness of MCI Handbook -based multidomain lifestyle interventions provided by nonprofessionals. Methods A 12-month intervention was implemented for older adults with mild cognitive impairment (MCI) recruited from two facilities in Japan. The feasibility outcomes included class participation rates and satisfaction with the intervention measured using the Japanese version of the 8-item client satisfaction questionnaire (CSQ-8J). Effectiveness was assessed based on changes in the Japanese version of the Montreal Cognitive Assessment (MoCA-J) scores. Results In total, 37 participants (16 males and 21 females; mean age, 78.6 years) were included. The mean class participation rate was 88.3 ± 17.7%, with high satisfaction reported by the participants (average CSQ-8J score, 25.6 ± 3.4). The MoCA-J score improved significantly from 21.9 ± 2.9 at baseline to 23.3 ± 3.8 at 12 months (p = 0.007), highlighting the clinical relevance of this intervention. Compared with the external control group, the intervention group showed significantly greater cognitive improvements (p = 0.017). Conclusions These findings demonstrate the feasibility and effectiveness of a 12-month multidomain lifestyle intervention conducted by nonprofessionals using the MCI Handbook . This program offers a promising, resource-efficient approach to dementia prevention. Future studies are needed to refine the delivery strategies and explore scalable methods for the broader implementation of multidomain interventions for dementia prevention.