Spousal loss and physical vulnerability: Diverging frailty trajectories by educational attainment in older adults.

Spousal loss is a major life event in later adulthood that can increase vulnerability to physical decline. Despite a growing body of research on spousal loss and health, less is known about its long-term impact on frailty, and whether this association varies by educational attainment. This study examines the longitudinal relationship between spousal loss and frailty among older adults and assess whether this relationship is moderated by education. Data were drawn from seven waves of the Korean Longitudinal Study of Ageing, a nationally representative panel survey of adults aged 45 and older (N = 7999). Frailty was assessed using a 41-item frailty index across seven domains. Distributed fixed effects regression models estimated within-person changes in frailty before and after spousal loss. Frailty increased before and shortly after spousal loss, but these associations weakened and became non-significant after adjusting for social and economic factors. Stratified analyses showed that spousal loss significantly increased frailty only among those with higher education, with elevated levels persisting for several years. No such effects were observed among those with lower education. Interaction models confirmed the significance of these educational differences. While no significant gender differences were found, the moderating effect of education was evident among those who experienced spousal loss at age 60 or older. These findings suggest that the impact of spousal loss on frailty is shaped by educational attainment, challenging assumptions about the uniformly protective role of education and underscoring the need for tailored interventions to address the diverse vulnerabilities of bereaved older adults.