The Mediating Role of Daily Living Autonomy in the Relationship Between Physical-Functional Fitness and Fear of Falling in Older Adults

Falls and Fear of Falling (FOF) are major public health concerns among older adults, impacting mobility, autonomy, and quality of life. This study aimed to investigate the multidimensional correlates of FOF, including clinical, cognitive, physical-functional, and functional autonomy factors, and to examine the mediating role of Instrumental Activities of Daily Living (IADL) in the relationship between physical function and FOF. A total of 278 older adults (mean age 81.9 ± 7.9 years) were assessed for sociodemographic, clinical, cognitive, nutritional, and physical-functional variables. Participants with higher FOF demonstrated greater comorbidity burden, higher depressive symptom scores, lower physical performance in most functional tests, and reduced IADL compared to those with lower FOF. Bivariate analyses showed moderate positive correlations of FOF with comorbidity burden (r = 0.323) and depressive symptoms (r = 0.343), and negative correlations with physical performance measures. Hierarchical regression revealed that IADL accounted for the largest incremental variance in FOF (ΔR² = 0.114), highlighting its central role. Mediation analysis confirmed that IADL fully mediated the relationship between physical function and FOF (ACME = − 5.46, p = 0.005), suggesting that the impact of physical function on FOF operates primarily through functional autonomy. These findings emphasize the importance of integrating functional autonomy, physical performance, and clinical factors in fall prevention strategies. A multidimensional, biosocial approach may improve the identification of high-risk individuals and guide targeted interventions to enhance safety, independence, and quality of life among older adults.