Abstract:Objective To investigate the risk factors of chronic postsurgical pain（CPSP） after lumbar internal fixation on elderly patients and establish a prediction model for it. Methods A retrospective analysis was performed on the clinical data of 80 elderly patients undergoing posterior lumbar internal fixation in Beijing Sixth Hospital from October 2018 to June 2022. With univariate analysis and multivariate logistic regression analysis, the risk prediction model was constructed, and its predictive performance for CPSP was verified by using feedback analysis of the confusion matrix. Results Out of 80 patients receiving posterior lumbar decompression and internal fixation, 27 patients developed CPSP（33.75%, 27/80）. Operation time（≥3h）, preoperative VAS score（≥6） and preoperative angiotensin Ⅱ type 2 receptor（AT2R） concentration（≥1000pg/mL） were the independent risk factors of CPSP（P<0.05）. According to the regression coefficients and constants of various variables by multivariate logistic regression analysis, the prediction model（Prob=1/（e-Y）, Y=4.285-1.013X1-1.187X2-1.276X3） of CPSP was constructed, which included three indicators, namely, the operation time（X1）, preoperative VAS score（X2） and preoperative AT2R concentration（X3）. ROC curve analysis showed that the sensitivity, specificity and area under the curve（AUC） of the model in predicting CPSP were 77.36%, 74.07% and 0.770, respectively（P<0.05）. The overall prediction accuracy of the model for CPSP was 75.00%（60/80） in the elderly after lumbar internal fixation. ConclusionsThe prediction model constructed based on the above-mentioned risk factors has good predictive performance and is conducive to early identification of high-risk elderly patients with CPSP in clinical practice.