Construction And Efficacy Evaluation Of Postoperative Blood Transfusion Prediction Model For Elderly Patients With Hip Fracture

Objective:Perioperative anemia in elderly patients with hip fractures occurs in high incidence.Severe anemia requires the therapeutic intervention of blood transfusion.However,blood transfusion is often accompanied by a poor prognosis.The purpose of this study is to find the risk factors related to postoperative blood transfusion and to establish a prognostic model to evaluate the risk of postoperative blood transfusion.The model can guide the prevention and treatment of anemia in perioperative elderly patients with hip fracture,reduce the rate of perioperative blood transfusion,promote early functional rehabilitation,and improve the final clinical prognosis.Methods:This study retrospectively analyzed the clinical data(age,gender,fracture type,preoperative complications,time from injury to operation,American Society of Anesthesiologists classificatio,mode of anesthesia,surgical duration,intraoperative blood loss,Whether to take orally traditional Chinese medicine prescription of peach kernel-safflower before operation)and preoperative laboratory indexes(hemoglobin,platelet count,international normalised ratio,serum albumin)of hip fracture patients aged≥ 65 who were hospitalized in the Department of Traumatic Orthopedics of the first affiliated Hospital of Guangzhou University of traditional Chinese Medicine from June2017 to June 2020.In this study,patients were divided into transfusion group and non-transfusion group based on whether they take postoperative blood transfusion.The best predictors of the model were screened by least absolute shrinkage and selection operator(Lasso)regression analysis,univariate analysis and multivariate binary logistic regression analysis.A nomogram model was constructed by using the R software based on the results of multivariate binary logistic regression analysis.Receiver operating characteristic curve(ROC curve)and C index were used to evaluate the discrimination of the model,and a calibration chart was established to evaluate the calibration degree of the prediction model.Decision Curve Analysis was applied to evaluate the clinical practicality.Bootstrap method is used for internal verification to evaluate the repeatability of modeling.Results:A total of 471 elderly patients with hip fractures were included in this study,and the postoperative blood transfusion rate was 26.1%.Multivariate regression analysis showed the related factors of postoperative blood transfusion: age ≥ 80 years(compared with age< 80 years,OR: 1.908,95%CI [1.104-3.299],P=0.021);femoral neck fracture(compared with femoral intertrochanteric fracture,OR: 0.560,95%CI [0.324-0.968],P=0.038);complicated with chronic obstructive pulmonary disease(OR: 2.427,95%CI [1.206-4.884],P=0.013);ASA grade ≥ Ⅲ grade(compared with ASA grade <Ⅲ grade,OR: 1.935,95%CI [1.151-3.252],P=0.013),intraoperative blood loss was 100-199 ml(compared with intraoperative bleeding volume < 100 ml,OR: 3.194,95%CI [1.718-5.939],P <0.001),intraoperative blood volume≥200 ml(compared with intraoperative blood volume < 100 ml,OR: 10.276,95%CI [5.005-21.098],P< 0.001).The admission HGB was 90-119 g/L(compared with admission HGB < 90 g/L,OR:0.303,95%CI [0.137-0.673],P=0.003),and the admission HGB ≥ 120 g/L(compared with admission HGB < 90 g/L,OR: 0.073,CI[0.029-0.189],P< 0.001).In terms of performance evaluation,the area under the ROC curve(AUC)and C index of the model were both 0.841,and the C index after internal verification and correction was 0.828.The original curve and correction curve of the calibration graph showed the similar slope as the ideal curve.The results of decision curve analysis showed that the model could benefit clinically when the risk threshold was between 4% and 97%.Conclusion:The nomogram model constructed in this study can accurately distinguish between high-risk and low-risk groups of postoperative blood transfusion in elderly patients with hip fracture.It can be used for individualized prediction of postoperative blood transfusion in elderly patients with hip fracture to help patients at high risk of severe anemia get benefit from treatment.