A Simple Preoperative Scoring System for Risk Stratification of Complicated Appendicitis in Children.

Background/

Objectives

Preoperative discrimination of complicated appendicitis in children remains challenging but crucial for timely surgical decision-making and perioperative management. We aimed to develop a simple, clinically applicable scoring system for preoperative risk stratification of complicated appendicitis in children.

Methods

This retrospective single-center study included children aged 5 to <16 years who underwent emergency appendectomy between 2015 and 2024. Complicated appendicitis was defined as gangrene, perforation, or intra-abdominal abscesses on intraoperative or pathological evaluation. Literature-based prespecified predictors included body temperature ≥ 38.0 °C, presence of periappendicular fluid, serum sodium level < 135 mEq/L, white blood cell (WBC) count > 12,000/μL, and C-reactive protein (CRP) level ≥ 3.0 mg/dL. A multivariable logistic regression model using Firth's penalized likelihood was developed and internally validated using bootstrap resampling. An additive scoring system was derived from the final model.

Results

Among 301 patients, 102 (33.9%) had complicated appendicitis. Based on the Firth penalized multivariable model, integer point values were assigned in proportion to the regression coefficients. Serum sodium level < 135 mEq/L and CRP level ≥ 3.0 mg/dL assigned 2 points each; body temperature ≥ 38.0 °C, presence of periappendicular free fluid, and WBC count > 12,000/μL assigned 1 point each. The scoring system (range, 0-7) demonstrated good discrimination (area under the receiver operating characteristic curve, 0.880; 95% confidence interval, 0.840-0.920), minimal optimism, and good calibration. Stratification into low-, intermediate-, and high-risk categories showed an increasing prevalence of complicated appendicitis.

Conclusions

This simple preoperative scoring system enables reliable and clinically interpretable risk stratification for complicated appendicitis in children aged 5 to <16 years and may support early decision-making in routine pediatric surgical practice.