Co-occurrence of Social Frailty and Reduced Ikigai and Their Association with Physical Function in Community-Dwelling Older Adults: A Cross-Sectional Study

• Co-occurrence of social frailty and reduced ikigai examined in 310 older adults. • Employment and economic sufficiency strongly protect against co-occurrence risk. • Physical and cognitive measures showed no independent association in multivariable analysis. • Findings highlight the need for social-health interventions in aging policy and practice. This study examined factors associated with the co-occurrence of social frailty and reduced ikigai (sense of life worth living) among community-dwelling older adults in Japan, with a focus on physical, cognitive, and socioeconomic contributors. A cross-sectional survey was conducted among 310 community-dwelling older adults. Social frailty was assessed using a validated five-item scale, and ikigai was measured using the K-1 scale. Reduced ikigai was defined using a distribution-based threshold. Physical function, cognitive function, lifestyle factors, and socioeconomic characteristics were evaluated. Participants were classified into four groups according to the presence or absence of social frailty and reduced ikigai. Group differences were examined, and multivariable logistic regression was used to identify factors associated with their co-occurrence. Of the participants, 22.6% exhibited co-occurrence of social frailty and reduced ikigai. Older age was associated with co-occurrence. In multivariable analyses, employment status and perceived economic sufficiency were independently associated with a lower likelihood of co-occurrence, whereas physical and cognitive function measures were not independently associated after adjustment. The co-occurrence of social frailty and reduced ikigai was more strongly associated with socioeconomic factors—particularly employment and perceived economic sufficiency—than with physical or cognitive function. These findings suggest that social and economic contexts play an important role in multidimensional vulnerability in later life. Longitudinal studies are needed to clarify causal pathways and to evaluate interventions that support meaningful social roles and participation among older adults.