分析老年结直肠癌患者术后腹腔感染的危险因素并构建预测模型，为临床早期识别与干预提供参考。

收集2017年1月至2023年12月嘉兴市第一医院收治的老年结直肠癌患者的临床资料，采用单因素与多因素Logistic回归分析筛选术后腹腔感染的危险因素构建预测模型。采用Hosmer-Lemeshow检验评估模型拟合优度。通过ROC曲线评估模型预测效能。

共纳入1 150例老年结直肠癌手术患者，其中97例（8.43%）发生腹腔感染。腹腔感染与非腹腔感染老年结直肠癌患者在术前肝功能异常、术前糖化血红蛋白A1c（Hemoglobin A1c, HbA1c）、术前肠梗阻、术前手术风险分级标准分级评分以及住院费用、术后住院时间、引流管置管时间、吻合口瘘、手术时间、手术分期、联合脏器切除术方面的差异均有统计学意义（P<0.05）。多因素Logistic回归分析显示，术前HbA1c升高（OR=1.480，95%CI：1.062~2.062，P<0.05）、术后住院时间≥11 d（OR=7.920，95%CI：2.272~27.616，P<0.05）、引流管置管时间≥9 d（OR=2.454，95%CI：1.114~5.404，P<0.05）、吻合口瘘（OR=3.361，95%CI：1.125~10.042，P<0.05）及手术分期Ⅳ期（OR=4.871，95%CI：1.126~21.067，P<0.05）是老年结直肠癌患者术后发生腹腔感染的危险因素。基于上述因素构建预测模型，Hosmer-Lemeshow检验显示模型拟合良好（χ²=5.007，P=0.659），曲线下面积为0.816（95%CI：0.771~0.862，P<0.05），在最佳概率阈值（0.089）下的模型灵敏度为89.09%、特异度为70.62%、约登指数为0.5971。

术前HbA1c升高、术后住院时间≥11 d、引流管置管时间≥9 d、吻合口瘘、手术分期Ⅳ期是老年结直肠癌患者术后腹腔感染的独立危险因素，以此构建的预测模型效能良好，可为临床早期识别与干预提供参考。

To analyze the risk factors and construct a predictive model for postoperative intra-abdominal infection in elderly colorectal cancer patients, so as to provide a reference for early clinical identification and intervention.

Clinical data of elderly patients with colorectal cancer admitted to the First Hospital of Jiaxing from January 2017 to December 2023 were collected. Univariate and multivariate logistic regression analyses were performed to identify risk factors for postoperative intraabdominal infection and to develop a prediction model. The Hosmer-Lemeshow test was used to assess the goodness of fit of the model, and the receiver operating characteristic (ROC) curve was applied to evaluate its predictive performance.

A total of 1150 elderly surgical patients with colorectal cancer were included, among whom 97 (8.43%) developed intra-abdominal infection. There were statistically significant differences between elderly patients with colorectal cancer who had intraabdominal infections and those without intraabdominal infections in terms of preoperative abnormal liver function, preoperative glycated hemoglobin A1c (HbA1c), preoperative intestinal obstruction, Preoperative surgical risk classification standard-classification score, hospitalization costs, postoperative hospital stay, drainage tube indwelling time, anastomotic leakage, operation time, pathological stage, and combined organ resection (P < 0.05). Logistic regression analysis showed that elevated preoperative HbA1c (OR=1.480, 95%CI: 1.062-2.062, P < 0.05), postoperative hospital stay≥11 days (OR=7.920, 95%CI: 2.272-27.616, P < 0.05), drainage tube indwelling time≥9 days (OR=2.454, 95%CI: 1.114-5.404, P < 0.05), anastomotic leakage (OR=3.361, 95%CI: 1.125-10.042, P < 0.05), and surgical stage Ⅳ (OR=4.871, 95%CI: 1.126-21.067, P < 0.05) were independent risk factors for postoperative intra-abdominal infection. Based on these factors, a prediction model was constructed. The Hosmer-Lemeshow test showed that the model fit was good (χ²=5.007, P > 0.05), with an AUC value of 0.816 (95%CI: 0.771-0.862, P < 0.05). At the optimal probability threshold of 0.089, the model achieved a sensitivity of 89.09%, a specificity of 70.62%, and a Youden index of 0.5971.

Elevated preoperative HbA1c level, postoperative hospital stay≥11 days, drainage tube indwelling time≥9 days, anastomotic leakage, and surgical stage Ⅳ are independent risk factors for postoperative intraabdominal infection in elderly patients with colorectal cancer. The constructed predictive model shows good discriminative ability and can serve as a reference for early identification and intervention in clinical practice.