BackgroundThe occurrence of complications following radical gastrectomy for gastric cancer significantly impacts patients’ quality of life. Elderly patients are susceptible to postoperative complications. This study seeks to investigate the risk factors associated with Clavien-Dindo ≥IIgrade complications following radical gastrectomy for advanced gastric cancer in elderly patients, develop a nomogram risk prediction model, and validate its accuracy.MethodsRetrospective collection of clinical and pathological data was conducted on 442 elderly patients with advanced gastric cancer who underwent radical gastrectomy at Shaanxi Provincial People’s Hospital from January 2015 to December 2020. They were randomly divided into a training set (n = 310) and a validation set (n = 132) in a 7:3 ratio. The severity of postoperative complications was graded using the Clavien-Dindo classification system, resulting in two complication groups: Clavien-Dindo <II group (n = 229) and Clavien-Dindo ≥II group (n = 81). Univariate and multivariate logistic regression analyses were performed to identify independent risk factors affecting the occurrence of Clavien-Dindo ≥II grade complications, and a predictive model was established based on the results. The model was then validated using the validation set.ResultsAmong the 442 patients included in the study, 121 cases (27.38%) experienced postoperative complications, with 111 cases (25.11%) classified as Clavien-Dindo ≥II grade complications. Multivariable logistic analysis revealed that the Prognostic Nutritional Index (PNI), surgical duration, age, and history of Diabetes mellitus were independent risk factors for the occurrence of Clavien-Dindo ≥IIgrade complications in elderly patients with advanced gastric cancer after surgery (P < 0.05). The nomogram model constructed based on these factors demonstrated good discriminative ability, as indicated by the area under the Receiver Operating Characteristic (ROC) curve. Calibration plots showed that the predicted probability of gastric cancer lymph node metastasis using the nomogram model was well aligned with actual outcomes. Decision curve analysis indicated the clinical utility of the nomogram model across a wide range of thresholds, demonstrating its practicality and potential for clinical benefit.ConclusionThis study identified Prognostic Nutritional Index (PNI), surgical duration, age, and history of Diabetes mellitus as risk factors for the occurrence of Clavien-Dindo ≥ II grade complications in elderly patients with advanced gastric cancer after surgery. Based on these four risk factors, a nomogram risk prediction model was constructed. This model can be used to personalize the prediction of the risk of Clavien-Dindo ≥ II grade complications occurring after surgery in elderly patients with advanced gastric cancer.