Hematocrit as the Best Predictor of Red Blood Cell Transfusion in Elderly Patients with Femoral Neck Fractures Undergoing Hip Hemiarthroplasty

Background Overestimation of blood transfusion in older patients with femoral neck fractures undergoing hip hemiarthroplasty results in unnecessary consumption of blood bank resources. Herein, we aimed to develop a preoperative predictive tool for appropriate red blood cell preparation. Methods A retrospective cohort study was conducted between January 2015 to October 2025. Univariate and multivariate logistic regression were used to identify predictive factors. The area under the receiver operating characteristic curve (AuROC) was used to evaluate significant factors. Predictive performance was validated using sensitivity, specificity, and positive and negative predictive values, and externally validated in independent cases. Results Among 424 patients, 135 patients received blood transfusion (31.84%). Preoperative hematocrit was the final predictor with AuROC of 0.95. Hematocrit was externally validated, which yielded an AuROC of 0.94. Preoperative hematocrit level at 33% showed sensitivity, specificity, and positive and negative predictive values of 84.44%, 91.70%, 82.61%, and 92.66% respectively. Conclusions Preoperative hematocrit is a simple and reliable predictor for packed red blood cell transfusion preparation in older patients undergoing hemiarthroplasty.