The impact of involvement in social activities on dementia onset: The role of willingness.

BackgroundImplementing dementia prevention measures is a critical global health objective.ObjectiveThis study investigated the impact of social activity involvement and willingness on dementia onset in community-dwelling older adults, and potential differences across age and sex subgroups.MethodsLongitudinal analysis was conducted on 2247 community-dwelling older adults ≥65 years (mean age: 74) who participated in the National Center for Geriatric and Gerontology-Study of Geriatric Syndromes in Japan (2015-2016 baseline survey) and were followed up at onset of dementia, including Alzheimer's disease, over 60 months. The Lifestyle Activities Questionnaire was used to determine social activity involvement. Willingness to participate in social activities was determined by asking if participants were willing to engage in 12 specific activities. Participants were classified into three groups: low-involvement, high-involvement/low-willingness, and high-involvement/high-willingness. Statistical analysis was conducted using Cox proportional hazards analysis with dementia onset as the outcome variable, involvement and willingness groups as explanatory variables, and adjusted covariates. Subgroup analyses examined differences across age and sex groups.ResultsThe high-involvement/high-willingness group showed a significantly lower dementia incidence (p < 0.001) than the other groups. Cox proportional hazards analysis revealed that the high-involvement/high-willingness group had a significantly lower hazard ratio (HR: 0.73, 95% confidence interval: 0.54-0.97) for dementia onset than the low-involvement group. This result was maintained in men and the age > 75 group.ConclusionsHigher involvement and willingness to participate in social activities lowered dementia risk, while higher involvement but low-willingness showed no protective effect. This result was maintained in men and the age > 75 group.