Aims: Hip fractures are associated with poor functional outcomes and increased mortality. The American College of Surgeons National Surgical Quality Improvement Program surgical risk calculator is an open access tool that predicts postoperative outcomes. This study aims to externally validate the accuracy of the calculator in predicting geriatric outcomes (new gait aid, delirium, functional decline, pressure ulcer), 30-day mortality and discharge destination in patients aged 65 and older undergoing surgical repair of neck of femur fractures.
Methods: A retrospective single-centre cohort study of patients admitted within a 12-month period (July 2022 to June 2023) was conducted. The calculator’s performance was analysed using the area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow test and Brier score statistics.
Results: 305 patients were included. Mean (SD) age was 82.4 (7.8) years and 215 (70.5%) were female. The calculator performed well for predicting delirium (AUC 0.86, 95% CI 0.81-0.90; Brier score 0.15), functional decline (AUC 0.88, 95% CI 0.83-0.94; Brier score 0.12) and mortality (AUC 0.85, 95% CI 0.77-0.92; Brier score 0.06). The Hosmer-Lemeshow test for these outcomes demonstrated good calibration. Analysis was unable to be performed for new gait aid. The calculator had reduced performance in predicting the other outcomes.
Conclusions: The calculator is a reliable predictor of delirium, functional decline and mortality in neck of femur fracture surgery. It has the potential to be incorporated into the shared decision making process for hip fracture management. Further research is required to validate it across other Australian healthcare settings.