Development and validation of a nomogram for predicting perforation in the early 24 h of acute appendicitis

This study aimed to develop and validate a nomogram prediction model for identifying the risk of early perforation (within 24 h) in patients with acute appendicitis, using objective clinical and imaging indicators.

A retrospective study was performed on 880 patients with acute appendicitis who underwent laparoscopic appendectomy within 24 h of symptom onset at the General Surgery Department of the Central Theater Command General Hospital between January 2011 and December 2022. Patients admitted from 2011 to 2020 were assigned to the modeling group (n = 616), and those from 2021 to 2022 to the validation group (n = 264). Based on postoperative pathology, patients were classified as having early or non-early perforated appendicitis. Independent risk factors for early perforation were identified using LASSO and multivariate logistic regression and were used to develop a predictive nomogram. Model performance was assessed by the area under the receiver operating characteristic (ROC) curve (AUC) for discrimination and the Hosmer-Lemeshow test for calibration.

Appendiceal diameter, body temperature, white blood cell count, fibrinogen level, appendiceal fecalith, age, and diabetes mellitus were identified as independent predictors of early perforation in acute appendicitis within 24 h (p < 0.05). ROC analysis indicated that diameter (AUC = 0.673), temperature (AUC = 0.705), white blood cell (AUC = 0.713), fibrinogen (AUC = 0.742), and age (AUC = 0.759) had moderate predictive power. Incorporating fecalith and diabetes significantly enhanced model performance, yielding an AUC of 0.891.

The nomogram prediction model incorporating appendiceal diameter, body temperature, white blood cell count, fibrinogen level, appendiceal fecalith, age, and diabetes mellitus demonstrates clinical utility in estimating the probability of perforation within 24 h in patients with acute appendicitis.