Construction and validation of a nomogram prediction model for the risk of delirium after hip arthroplasty in elderly patients

The aim of this study was to analyze the risk factors of postoperative delirium in elderly hip arthroplasty patients and to construct and validate a nomogram model. The clinical data of elderly patients with hip arthroplasty admitted to our hospital from January 2022 to December 2023 were retrospectively collected. Univariate and multivariate logistic regression analyses were used to determine the independent risk factors for delirium risk after hip arthroplasty in elderly patients, and the corresponding nomogram was established. Receiver operating characteristic curves and calibration curves were plotted to assess model performance. To further improve the reliability of the validation results, internal validation was performed using Bootstrap combined with 10-fold cross-validation rows to assess the clinical utility of the model using decision curve analysis. A total of 427 elderly hip replacement patients were enrolled in the study, and 74 patients experienced postoperative delirium, with an incidence rate of 17.33%. After univariate and multivariate logistic regression analyses, a total of 5 variables were identified as independent risk factors for postoperative delirium in elderly patients with hip arthroplasty: age >75 years (odds ratio [OR], 4.042; 95% confidence interval [CI], 2.129–8.244), cardiovascular disease (OR, 2.887; 95% CI, 1.584–5.347), duration of surgery >90 minutes (OR, 3.112; 95% CI, 1.118–6.839), resuscitation time >60 minutes (OR, 5.099; 95% CI, 2.632–9.837) and postoperative hypoxemia (OR, 4.244; 95% CI, 1.633–7.986). The nomogram constructed in this study for the risk of postoperative delirium in elderly patients with hip arthroplasty has good predictive accuracy and helps physicians to intervene in advance in elderly patients at high risk of postoperative delirium after hip arthroplasty.