DIAGNOSTIC ACCURACY OF NEUTROPHIL-TO-LYMPHOCYTE RATIO VS SMART-LAB SCORING SYSTEM IN DIAGNOSING COMPLICATED APPENDICITIS

Abstract

Background: Acute appendicitis is one of the most common causes of emergency abdominal surgery. Differentiating between uncomplicated and complicated appendicitis is crucial, as the latter requires urgent surgical management to prevent severe complications such as peritonitis and sepsis. Single biomarkers like the neutrophil-to-lymphocyte ratio (NLR) have been explored as diagnostic tools, but their accuracy is limited. More comprehensive scoring systems, such as SMART-LAB, may provide superior diagnostic reliability.

Objectives: To evaluate and compare the diagnostic accuracy of NLR and the SMART-LAB scoring system in distinguishing between complicated and uncomplicated appendicitis.

Methods: This cross-sectional study included 95 adult patients with acute appendicitis admitted to the Department of General Surgery, Saveetha Medical College and Hospital, Chennai, from January to December 2024. Patients with recurrent, subacute, or previously treated appendicitis were excluded. NLR values and SMART-LAB scores were calculated at admission. Intraoperative findings classified cases as uncomplicated or complicated appendicitis. ROC curve analysis was performed to determine area under the curve (AUC), cutoff values, sensitivity, and specificity for both tools.

Results: NLR showed an AUC of 0.670, with a sensitivity of 72.7% and specificity of 68.4% at a cutoff value of 5.68. The SMART-LAB scoring system demonstrated superior diagnostic accuracy, with an AUC of 0.816, sensitivity of 81.8%, and specificity of 68.4% at a cutoff of 8.

Conclusion: NLR is a simple and cost-effective biomarker for assessing appendicitis severity but demonstrates only moderate accuracy. The SMART-LAB scoring system, by integrating multiple clinical and laboratory parameters, showed significantly better diagnostic performance in distinguishing complicated from uncomplicated appendicitis. Its use in clinical practice may enhance decision-making, reduce delays in surgical intervention, and optimize healthcare outcomes.