Prognostic performance of clinical assessment tools following hip fracture in patients with chronic kidney disease

PURPOSE: People living with chronic kidney disease (CKD) are at a higher risk of hip fracture with an associated increased mortality risk compared to individuals without CKD. Our study aimed to evaluate the clinical assessment tools that best predict mortality risk following hip fracture for patients with CKD. METHODS: Patients with CKD G3b-5D admitted to Lancashire Teaching Hospitals NHS Foundation Trust, U.K. between June 2013 and Dec 2019 were included. The association between CKD and post-fracture mortality risk was evaluated. All patients were assessed using tools that evaluated frailty status, co-morbidity, pre-operative risk, functional status and cardiopulmonary fitness. Receiver operating characteristic curve analyses were performed to determine the prognostic accuracy of the assessment tools for 30 day and 1 year mortality following hip fracture in patients with CKD. RESULTS: 397 patients fulfilled inclusion criteria with a mean age of 83.5 ± 9.2 years. Older age, female sex, intracapsular fracture and more severe CKD, co-morbidity and frailty status were all associated with an increased mortality risk. Patients with dialysis-dependent CKD and severe/very severe frailty had a hazard ratio for mortality of 2.55 (95% Cl 2.11–2.98) and 3.11 (95% Cl 2.47–3.93), respectively. The Clinical Frailty Scale demonstrated the best prognostic accuracy for both 30 day [Area Under the Curve (AUC) 0.91, 95% Cl 0.84–0.97] and 1 year mortality (AUC 0.93, 95% Cl 0.87–1.00). CONCLUSION: Patients with advanced CKD and severe frailty have a high mortality risk following hip fracture. The Clinical Frailty Scale is an excellent prognostic tool for mortality in this setting and could be easily incorporated into routine clinical practice.