C-reactive Protein, Absolute Neutrophil Count, and Appendix Wall Thickness in Predicting Appendicitis Severity and Outcomes: A Retrospective Study

Abstract Background: Acute appendicitis is a common emergency that requires prompt diagnosis and treatment to avoid complications. The combined use of biomarkers, such as C-reactive protein (CRP), absolute neutrophil count (ANC), and appendix wall thickness, is frequently evaluated for its clinical utility in diagnosing severe appendicitis using objective tools like receiver operating characteristic (ROC) analysis. Objectives: To assess the diagnostic performance of CRP, ANC, and appendix wall thickness in identifying severe appendicitis and associated complications. Design: Retrospective cohort study. At Al-Thowra General Modern Hospital, a tertiary referral hospital. Patient and Methods: Patients aged 18–65 years with confirmed acute appendicitis based on clinical, laboratory, and imaging findings were included. CRP, ANC, and appendix wall thickness were measured and analyzed using ROC analysis to evaluate their diagnostic accuracy for appendicitis severity. Statistical analyses were conducted using SPSS software (version 23).” Main Outcome Measure: Diagnostic performance of CRP, ANC, and appendix wall thickness in identifying severe appendicitis and complications, including perforation and abscess formation. Sample Size: 200 patients. Results: CRP had low diagnostic performance, with an area under the curve (AUC) =0.52. Appendix wall thickness demonstrated moderate diagnostic performance (AUC = 0.74), while ANC also showed moderate diagnostic performance (AUC = 0.71). Combining CRP, ANC, and appendix wall thickness did not significantly enhance diagnostic accuracy (AUC = 0.71). Patients with elevated CRP (>100 mg/L), appendix wall thickness (>7 mm), and ANC (>12,000 cells/μL) were more likely to develop complications, such as perforation and abscess formation ( P < .001). These patients also had significantly longer hospital stays compared to those with lower biomarker values ( P < .001. Conclusion: Appendix wall thickness and ANC demonstrated moderate diagnostic accuracy for identifying severe appendicitis, while CRP showed limited diagnostic utility. The combined use of these markers aids in risk stratification and clinical decision-making but did not significantly outperform individual markers. Limitations: Single-center retrospective study; variability in ultrasound measurements Conflict of interest: None.