Abstract: Objective To analyze risk factors for perioperative blood transfusion in elderly patients undergoing unilateral primary total hip arthroplasty and develop a prediction model. Methods The study retrospectively collected 467 elderly patients receiving unilateral primary total hip arthroplasty between January 2013 and October 2021 at Peking Union Medical College Hospital. The 70% of the data were used as the training set and the 30% of the data were used as the testing set. Patients were divided into the transfusion and no-transfusion groups based on the presence or absence of perioperative blood transfusion. Univariate analysis and multivariable logistic regression were conducted to analyze patient demographic characteristics, surgical information, and preoperative laboratory tests for identifying risk factors. Clinical experience was combined to establish a prediction model and draw the nomogram. The receiver operating characteristic(ROC) curve and calibration curve were used to evaluate the model in the testing set. Results A total of 91 patients(19.5%) received perioperative blood transfusion. Multivariable logistic regression suggested the history of coronary artery disease, prolonged operation time, and lower preoperative hemoglobin were risk factors for perioperative blood transfusion(P＜0.05). The prediction model was constructed based on the results of statistical analysis and clinical experience, including the history of coronary artery disease, operation time, preoperative hemoglobin, age, and American Society of Anesthesiologists(ASA) physical status＞Ⅱ. The area under the receiver operating characteristic curve(AUC) of the model was 0.809. Conclusions The prediction model for perioperative blood transfusion in elderly patients undergoing unilateral total hip arthroplasty had a good performance and could assist in clinical practice.

Key words: perioperative blood transfusion, total hip arthroplasty, elderly patients, blood transfusion risk prediction