The Sensitivity and Specificity of White Blood Cell Count as a Biomarker for the Diagnosis of Acute Appendicitis

Abstract

Introduction: The diagnosis of acute appendicitis is largely clinical. However, diagnostic difficulties may arise with many cases resulting in significant morbidity and mortality. The diagnostic and discriminatory values of white blood cell (WBC) count in acute appendicitis have been studied extensively, but the results remain controversial. This study aimed to assess the sensitivity and specificity of WBC count as a biomarker for the diagnosis of acute appendicitis Materials and Methods: This was a one-year prospective hospital-based study carried out on sixty-six (66) consecutive patients presenting to the accident and emergency ward, who had appendicectomy following a clinical diagnosis of acute appendicitis. Before surgery, samples for WBC count were collected from all recruited patients. Intraoperative macroscopic assessment and histopathological examination were done for all appendixes. A proforma was used to collect data. All the statistical analyses were performed using statistical package for social sciences (IBM SPSS) version 21. Calculations of mean, standard deviations, and associations between the variables were tested for statistical significance using appropriate statistical tools. p-values less than 0.05 were considered significant. Results: The median age was 25 years and male: female ratio was 1:1.8. Thirteen of the appendixes removed had normal histopathologic examination. The diagnostic accuracy, sensitivity, specificity and positive predictive value for preoperative WBC count were 73%, 72%, 77% and 93% respectively. Conclusion: The diagnosis of appendicitis should be made primarily based on clinical findings. All patients with suspected acute appendicitis should have WBC count done. If the WBC count is normal, acute appendicitis is very unlikely.