Frailty is More Predictive of Mortality than Age in Patients with Hip Fractures

Abstract

OBJECTIVES: To investigate the association between the Comprehensive Geriatric Assessment-based Frailty Index (FI) and adverse outcomes in older adult patients undergoing hip fracture surgery. METHODS: Design: Retrospective cohort study Setting: Academic Level 1 Trauma Center. Patients: All patients aged 65 or older who underwent surgical repair of a hip fracture between May 2018 and August 2020 were identified through institutional database review. Outcome Measures and Comparisons: Data including demographics, FI, injury presentation, and hospital course were collected. Patients were grouped by FI as non-frail (FI < 0.21), frail (0.21≤FI<0.45), and severely frail (FI >0.45). Adverse outcomes of these groups were compared using Kaplan Meier survival analysis. Risk factors for one-year re-hospitalization and two-year mortality were evaluated using Cox hazard regression. RESULTS: 316 patients were included, with 62 non-frail, 185 frail, and 69 severely frail patients. The total population was on average 83.8 years old, predominantly white (88.0%), and majority female (69.9%) with an average FI of 0.33 (SD: 0.14). The non-frail cohort was on average 78.8 years old, 93.6% white, and 80.7% female; the frail cohort was on average 84.5 years old, 92.4% white, and 71.9% female, and the severely frail cohort was on average 86.4 years old, 71.0% white, and 55.1% female. Rate of one-year readmission increased with frailty level, with a rate of 38% in non-frail patients, 55.6% in frail patients, and 74.2% in severely frail patients (p=0.001). The same pattern was seen in two-year mortality rates, with a rate of 2.8% in non-frail patients, 36.7% in frail patients, and 77.5% in severely frail patients (p<0.0001). Being classified as frail or severely frail exhibited greater association with mortality within 2 years than age, with hazard ratio of 17.81 for frail patients and 56.81 for severely frail patients compared to 1.19 per 5 years of age. CONCLUSIONS: Increased frailty as measured by the Frailty Index is significantly associated with increased two-year mortality and one-year hospital readmission rates following hip fracture surgery. Degree of frailty predicts mortality more strongly than age alone. Assessing frailty with the Frailty Index can identify higher-risk surgical candidates, facilitate clinical decision-making, and guide discussions about goals of care with family members, surgeons, and geriatricians. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.