A comparative study on the diagnostic validity of three scoring systems in the diagnosis of acute appendicitis in emergency centres

Background: Considering the inconsistencies on the validity scoring systems in the diagnosis of acute appendicitis, our aim was to compare the accuracy of the three Anderson, Alvarado and Alvarado + CRP scoring systems in the diagnosis of patients with suspected acute appendicitis. Methods: This was a prospective observational study performed on patients 15-65 years complained of abdominal pain in the RLQ with a high clinical suspicion of acute appendicitis within two years. The scoring systems of Anderson, Alvarado, and Alvarado + CRP were recorded using a pre-prepared questionnaire by a senior emergency medicine assistant. Acute appendicitis was confirmed based on the histopathologic findings. Written informed consent was obtained from all the patients before entering the study. Results: 200 patients were enrolled in the study. In 159 cases diagnosed with appendicitis based on histopathological findings, Anderson, Alvarado, and Alvarado scoring systems were able to identify 121, 152, and 147 cases respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 77%, 19%, 78%, 17 and 64% in Anderson, 95%, 7%, 75%, 30% and 77% in Alvarado, and 92%, 7%, 79%, 20%, and 75% in Alvarado + CRP scoring systems, respectively. Conclusion: Anderson scoring system had lower diagnostic accuracy than the Alvarado system. The role of CRP as an adjunct test to increase the accuracy of the Alvarado scoring system in the diagnosis of acute appendicitis has been under question. Given the inconsistent results of the scoring systems in the diagnosis of acute appendicitis, there is a need to develop a more precise clinical-paraclinical scoring system for this condition.