Association of preoperative frailty and postoperative delirium with one-year mortality after surgery in older patients with hip fractures

Background We aimed to evaluate the incidence of preoperative frailty and postoperative delirium (POD) and the association of preoperative frailty, POD with one-year mortality in older patients undergoing hip fracture surgery. Methods Patients with hip fracture were identified from 2018 to 2023 in our hospital. The patients were categorized into four groups: patients without preoperative frailty who did not suffer from POD, patients without preoperative frailty who did suffer from POD, patients with preoperative frailty who did not suffer from POD, and patients with preoperative frailty who did suffer from POD. The primary outcome was one-year mortality after surgery. Multivariate landmark Cox regression analysis was used to assess the associations of preoperative frailty and POD with one-year mortality, and adjusted survival curves from the multivariate Cox model were plotted. Results Of 2,659 patients, 1,715 were included in the final analysis. The incidence of preoperative frailty was 24.0% (411/1715), and the POD rate was 16.9% (290/1715). Compared with older patients without preoperative frailty who did not suffer from POD (5.6%, 61/1088), the incidence of one-year mortality was significantly higher in patients without preoperative frailty who did suffer from POD (17.1%, 37/216), patients with preoperative frailty who did not suffer from POD (11.6%, 39/337), and patients with preoperative frailty who did suffer from POD (28.4%, 21/74). Preoperative no-frailty and POD (HR: 2.09, 95% CI: 1.36–3.21), frailty and no-POD (HR: 2.30, 95% CI: 1.51–3.50), and frailty with POD (HR: 3.95, 95% CI: 2.35–6.63) were all independently associated with one-year mortality after surgery in older patients with hip fracture. Conclusion Preoperative frailty and POD were each independently associated with increased one-year mortality. Patients with both conditions had the highest observed mortality risk after hip fracture surgery.