Community-based going-out program and dementia onset in Japanese older adults: A longitudinal observational study.

Objectives: With dementia prevalence rising globally among older adults, effective and scalable community-based interventions are urgently needed to reduce dementia onset. This study aimed to estimate the association of the going-out program with dementia onset in older adults.

Methods: A 5-year longitudinal observational study was employed. Following a baseline assessment in 2015 and 2017, we observed 2,977 individuals engaging in a community-based going-out program for 12 months in Japan. Participants with continuous data over 12 months were defined as the engaged group, while those without such data were classified as the non-engaged group. After propensity score matching, 1,690 participants were selected. Dementia onset was obtained from the Japanese National Health Insurance and Later-Stage Medical Care System for 48-month follow-up. Incidence of dementia, absolute risk reduction (ARR), and number needed to treat (NNT) were calculated. The Cox proportional hazards model was used to estimate the effect of engagement in the program on dementia onset and to calculate a hazard ratio and 95 % confidential interval (CI).

Results: The incidence of dementia onset was 59 out of 845 (7.0 %) in the non-engagement group and 34 out of 845 (4.0 %) in the engagement group. The ARR rate was 3.0 % (95 % CI 0.8, 5.2), and the NNT was 33 (95 % CI 19, 125). The hazard ratio was 0.57 (95 % CI 0.37, 0.86).

Discussion: Engagement in the going-out program resulted in a 3.0 % reduction in the risk of dementia onset. The going-out program, which can be implemented in communities, holds potential efficacy in preventing dementia onset.