Identifying frailty in acutely hospitalised patients with hip fracture: are the clinical frailty scale and irish hip fracture database frailty index comparable for predicting adverse outcomes?

Purpose: Frail older adults are at increased risk of adverse outcomes after hip fracture. We compared the Clinical Frailty Scale (CFS) and the Irish Hip Fracture Database Frailty Index (IHFD FI) in predicting hospital outcomes.

Methods: A secondary analysis of national clinical audit data from two trauma units was conducted. The CFS and IHFD FI were derived from routinely collected data. Multivariable logistic regression assessed the predictive value of age, sex, ASA grade, plus either frailty tool for the following outcomes: delirium (positive 4AT and/or clinical diagnosis), inpatient mortality, prolonged length of stay (LOS ≥ 30 days) and discharge home within 14 days. Predictive performance was evaluated using area under the curve (AUC).

Results: The study included 1,388 patients discharged between 1st January 2022 and 31st December 2023 (mean age 80.0, 68.4% female). Delirium occurred in 39.1%, inpatient mortality in 5.2%, prolonged LOS in 22.2% and 33.6% were discharged home within 14 days. CFS data were available for 84.4% and IHFD FI for 86.5%. When added to age, sex and ASA, the CFS outperformed the IHFD FI for predicting delirium (AUC 0.816 vs. 0.790), while the IHFD FI was better for mortality (AUC 0.778 vs. 0.744). Both tools performed similarly for prolonged LOS and discharge home.

Conclusion: Both the CFS and IHFD FI were predictive of outcomes. However, the CFS demonstrated superior predictive value for delirium during admission. Prospective collection of the CFS is recommended to enhance the identification of patients at risk of delirium and to support timely clinical interventions.