Validating the Factor Structure of the Fujisawa Social Capital Scale (FSCS) Among Community-Dwelling Older Adults Participating in “Kayoi-no-ba”: The Gunma Aging Cohort Study

Social capital is a fundamental social determinant of health for older adults in rapidly aging societies; however, existing comprehensive instruments often impose high cognitive friction through complex recall tasks, potentially leading to systematically excluding vulnerable populations. This study validated the factor structure of the Fujisawa Social Capital Scale (FSCS) - an independent, brief tool designed for inclusive community-based practice - among community-dwelling Japanese older adults participating in "Kayoi-no-ba" (neighborhood social participation hubs). Data were analyzed from 587 participants in the Gunma Aging Cohort (mean age 79.2 ± 6.0 years; 87.1% female; 29.6% living alone). Exploratory factor analysis using the Weighted Least Squares Mean- and Variance-adjusted estimator was prioritized to ensure statistical stability for this specific cohort. A robust two-factor structure emerged: Factor 1, "Sense of Security and Attachment to the Community," and Factor 2, "Mutual Aid Among Neighbors." These findings underscore the conceptual distinction between psychological belonging and functional support within community settings. The model demonstrated favorable fit indices, with a Root Mean Square Error of Approximation of 0.071 and a Tucker-Lewis Index of 0.96. High internal consistency was confirmed using McDonald's omega (ω) for the total scale (ωt = 0.85), Factor 1 (ω = 0.77), and Factor 2 (ω = 0.74). Overall, these results indicate that the FSCS is a "practice-first" instrument that minimizes respondent burden while maintaining data reliability. By distinguishing psychological attachment from functional support, it provides a "common language" for interdisciplinary teams to guide social prescribing and prioritize targeted community-based support for socially vulnerable older adults.