Physical Resilience After Hip Fracture: Unpacking the Roles of Resistance and Recovery

Physical resilience-the ability to withstand, recover, or adapt after a stressor-is critical in older adults facing acute insults. We conceptualize physical resilience to comprise two distinct but related components: resistance (immediate physiological response to the stressor) and recovery (subsequent health changes). These two components were used to evaluate how individuals respond to hip fracture-a common and severe geriatric stressor.

Using data from nearly 5000 hip fracture participants, we used linear mixed-effects models to characterize a composite health status, derived from electronic health record diagnoses, 1 year before and after hip fracture. Resistance was assessed as the abrupt change in composite health status immediately after the fracture, whereas recovery represented the subsequent rate of change. We used Cox and Fine-Gray models to identify the associations of resistance and recovery with all-cause and cause-specific mortality, respectively.

We observed a significant and sharp decline in the composite health measure at the time of hip fracture. Following the fracture, the rate of health deterioration accelerated compared to the pre-fracture period. Lower resistance was associated with a 7% increase in mortality (95% CI = 1.06, 1.08); slower recovery was associated with a more than 2-fold increase in mortality (HR = 2.23, 95% CI = 2.05, 2.44). Lower resistance was associated with increased neurodegenerative mortality, whereas lower recovery was associated with increased mortality across most causes of death.

Physical resilience is a complex and dynamic process strongly linked to mortality outcomes post-hip fracture. Identifying individuals with lower resilience may improve clinical interventions to enhance recovery and reduce mortality.