Role of Individual Social Capital in the Association of Physical Frailty With Functional Ability Among Older Adults.

ABSTRACT

OBJECTIVES: Rich social capital is regarded as an individual's social asset, which may contribute to the maintenance of functional ability, even in a state of frailty. This study examined the moderating role of individual social capital in the association between physical frailty and functional ability among older adults. DESIGN: A cross-sectional study. SETTING AND PARTICIPANTS: In total, 522 community-dwelling older adults aged ≥60 years were recruited from among visitors to public facilities, including community cultural centers and gymnasiums in Aichi, Japan. METHODS: Functional ability was assessed using the 5-item subscale of the Tokyo Metropolitan Institute of Gerontology Index of Competence that assesses instrumental self-maintenance, including transportation, finance management, and shopping. Physical frailty was defined by the Fried Frailty Phenotype Questionnaire, including 5 items of fatigue, resistance, ambulation, inactivity, and weight loss, and the participants were classified into 3 groups non-frailty, pre-frailty, and frailty. Individual social capital was assessed for 2 dimensions the cognitive dimension (perceptions of community social cohesion) and the structural dimension (informal socializing and social participation). RESULTS: The participants' mean age (SD) was 74.1 (6.5) years and 78.0% were women. Among the participants, non-frailty was 46.6%, pre-frailty was 47.0%, and frailty was 6.5%. Multivariable linear regression analysis revealed that physical frailty was associated with lower levels of functional ability compared with non-frailty [pre-frailty ß (95% CI) = -0.07 (-0.22 to 0.08), P = .374; frailty ß = -0.67 (-0.99 to -0.35), P < .001]. However, individual structural social capital showed a negative interaction with physical frailty against low functional ability, indicating a moderating association (P = .027). CONCLUSIONS AND IMPLICATIONS High levels of individual structural social capital mitigated the adverse association between physical frailty and functional ability. Fostering rich social capital may preserve the functional ability of frail older adults, helping their independent lives in the community.