The effect of frailty on outcomes of surgically treated hip fractures in older people

Background: Hip fractures are associated with mortality, disability, and loss of independence in older adults. While several risk factors associated with poor outcomes following a hip fracture have been identified, the effect of frailty status prior to hip fracture is not well established. Aim: To examine the associations of frailty with mortality, change in activities of daily living (ADL) limitations, and transition to permanent residential aged care in older people following a hip fracture. Methods: A retrospective cohort study was conducted on people aged 65 years and older with a surgically treated hip fracture between 2003 and 2015. Frailty was estimated using a cumulative deficit-based frailty index and categorized into quartiles. Cox multivariable regression, logistic regression, and Fine-Gray multivariable regression models estimated associations of frailty with mortality, ADL limitations, and entry into permanent residential aged care, respectively. Hazard ratios (HR), odds ratios (OR), subdistribution hazard ratios (SHR), and 95% confidence intervals (95%CI) are reported. Results: Out of 4771 individuals with hip fractures, 75.6% were female and the median age was 86 (interquartile range 82-90) years old. The two-year survival of patients following hip fracture was 43.7% (95%CI 40.9-46.7%) in those in the highest quartile of frailty, compared to 54.4% (95%CI 51.8-57.2%) for those in the lowest quartile (HR = 1.25, 95%CI 1.11-1.41, p < 0.001). No associations between pre-fracture frailty and post-fracture ADL limitations were observed. Additionally, no association of frailty with transition to permanent residential aged care for patients living in the community (n = 1361) was observed (SHR = 0.98, 95%CI 0.81-1.18, p = 1.000). Conclusions: Older patients with the highest level of frailty had an increased risk of mortality after hip fracture. Consideration for appropriate clinical interventions, including fall and frailty prevention measures, may be appropriate for this identified group of vulnerable individuals.