Abstract:Objective To analyze the factors influencing postoperative bleeding in patients undergoing tonsillectomy and to develop and validate a nomogram prediction model to estimate the risk of postoperative bleeding.Methods A retrospective analysis of the clinical data from 508 patients who underwent tonsillectomy in the Department of Otolaryngology-Head and Neck Surgery of Xi'an People's Hospital from January 2018 to January 2023 was conducted. Patients were divided into bleeding and non-bleeding groups based on the occurrence of postoperative bleeding. Univariable analysis was performed on clinical data of both groups to identify variables with statistical significance, which were then included in multivariable Logistic regression analysis to construct a nomogram prediction model. Receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated to evaluate the predictive efficiency of the model.Results There was no statistically significant difference between the two groups in terms of sex composition, history of smoking and alcohol consumption, season of surgery, history of recurrent inflammatory reactions, intraoperative blood loss, surgical sites, prothrombin time, activated partial thromboplastin time, platelet count, red blood cell count, and neutrophil count (P > 0.05). The age, degree of tonsil embedding, postoperative infections, surgical duration, surgeon's experience, and white blood cell (WBC) count were different between the two groups (P < 0.05). The multivariable Logistic regression analysis indicated that age < 18 years [O^R = 214.062 (95% CI: 2.536, 18 065.451)], severe tonsil embedding [O^R = 34.602 (95% CI: 1.592, 751.844) ], postoperative infections [O^R=16.817 (95% CI: 1.088, 259.896) ], long surgical duration [O^R = 3.062 (95% CI: 1.588, 5.907) ], surgeon's experience < 6 years [O^R = 24.520 (95% CI: 1.795, 334.98) ] and high WBC count [O^R = 2.625 (95% CI: 1.161, 5.935) ] were risk factors for postoperative bleeding in patients undergoing tonsillectomy (P < 0.05). The nomogram model for postoperative bleeding after tonsillectomy demonstrated a good fit as assessed with the calibration curve (P < 0.05). The ROC curve analysis exhibited that the AUC of the combined detection was the highest being 0.979 (95% CI: 0.950, 1.000), with the highest sensitivity being 95.2% (95% CI: 0.762, 0.999), and the highest specificity being 94.9% (95% CI: 0.925, 0.967).Conclusions Age under 18 years, severe tonsil embedding, postoperative infections, prolonged surgical duration, surgeon's experience less than 6 years, and high WBC count are independent risk factors for postoperative bleeding in patients undergoing tonsillectomy. The nomogram prediction model serves as an effective tool for clinicians to assess the risk of postoperative bleeding.