Analysis of risk factors for prolonged postoperative hospital stay in patients after spinal tuberculosis lesion removal and fusion with internal fixation and development of a predictive model

English Keywords:Spinal tuberculosis  Length of hospital stay  Risk factors  Predictive model  Nomogram

English Abstract:

  【Abstract】 Objectives: To explore the risk factors related to the prolonged postoperative length of hospital stay(LOS) in patients after spinal tuberculosis lesion removal and fusion with internal fixation, and to construct a nomogram prediction model, so as to provide a theoretical basis for the enhanced recovery management of spinal tuberculosis patients.　Methods: The clinical data of 142 patients with spinal tuberculosis who underwent lesion removal and fusion with internal fixation in the Department of Orthopedics of the Affiliated Hospital of Zunyi Medical University between December 2018 and June 2023 were retrospectively analyzed. The patients were randomly divided into modeling group(n=96) and validation group(n=46) in a 2∶1 ratio. Setting the postoperative LOS>21d as the outcome variable for prolonged LOS, and taking age, gender, alcohol history, smoking history, hypertension, coronary heart disease, diabetes, anemia, postoperative hypoproteinemia, spinal cord injury, tuberculosis in other parts, bone destruction, blood transfusion, removal time of drainage, postoperative complications, operative time, blood loss, preoperative American Society of Anesthesiologists(ASA) score, postoperative ASA score, surgical incision length, pus formation, chemotherapy before surgery, and chemotherapy regimens as independent variables to develop univariate logistic regression model. The risk factors screened after univariate analysis were included for multivariate logistic regression model to determine the independent risk factors for LOS>21d after lesion removal and fusion with internal fixation in patients with spinal tuberculosis and to construct a predictive model for risk factors. The area under the curve(AUC) of receiver operating characteristics(ROC) curve was used to assess the the differentiation of the model; Calibration curve was used to assess the calibration situation of the model; Decision curve analysis(DCA) was used to assess the clinical value and influence of the model on actual decision-making process. Data of validation group was applied to draw ROC curve and calibration curve for external verification. Results: Univariate and multivariate analyses revealed that age(OR=1.040, 95% CI: 1.011-1.069), tuberculosis at other sites(OR=2.867, 95% CI: 1.157-7.106), and preoperative ASA score(OR=1.543, 95% CI: 1.015-2.347) were the independent risk factors for prolonged postoperative hospitalization in patients with spinal tuberculosis after lesion removal and fusion with internal fixation. The AUC of ROC curves of modeling group and validation group were 0.767(95% CI: 0.671-0.863) and 0.720(95% CI: 0.569-0.871), respectively, suggesting the predictive model had good predictive efficiency. The results of the calibration curve analysis demonstrated that the actual curve roughly resembled the ideal curve, and DCA curve revealed that the nomogram had superior clinical benefits. Conclusions: The spinal tuberculosis patients who are at older age, combined with other sites of tuberculosis, and with high preoperative ASA score are prone to prolonged LOS after lesion removal and fusion with internal fixation, and the risk prediction nomogram model developed accordingly has great predictive efficiency.