Socioeconomic Status Across the Life-Course and Frailty in Older Age: Evidence From Switzerland.

Objectives: This study examines how different measures of socioeconomic status (SES) across childhood and adulthood relate to frailty in older age.

Methods: Data came from the Lausanne cohort 65+ (Lc65+), a population-based study of approximately 4,500 older adults followed over 20 years. SES measures included education in young adulthood, occupational class in midlife, and specific early old-age factors: perceived income, wealth, financial strain, and receipt of financial subsidies. Frailty trajectories over a 10-year period were assessed using Fried's frailty phenotype and group-based trajectory modeling. Logistic regression models adjusted for sex, age, cohort, living situation, marital status, and number of children.

Results: Lower education, occupational class, financial strain, and financial subsidies in older age were each independently associated with higher frailty risk at ages 65-70. Financial strain and financial subsidies in early old age increased odds of medium- (aOR, 1.48-1.69) and high-frailty (aOR, 2.07-2.28) trajectories.

Conclusion: SES across the life course strongly correlates with frailty in early old age. Early interventions and financial protection policies in older age could help mitigate frailty risk and SES-related frailty inequalities.