Retrospective cohort: Comparison of clinical prediction rules for patients presented to AED with suspected acute appendicitis

Abstract Background Acute appendicitis is one of the common surgical emergencies with potential life‐threatening complications. Patients seldom present with typical features of migratory pain at the lower right quadrant. To avoid any unnecessary radiological risk from computed tomography or anesthetic and surgical risks, multiple predicting systems of acute appendicitis have been developed. Objective To compare the diagnostic accuracy of various clinical prediction rules among patients with suspected acute appendicitis. Materials and Methods Patients presenting to Emergency Department in Tuen Mun Hospital with abdominal pain from 1/1/2020 to 31/12/2022 were evaluated retrospectively. RIPASA, Alvarado and modified Alvarado scores were chosen to calculate and compare with radiological and/or histological results by reviewing the patients' clinical data through the hospital electronic system. Results A total of 340 patients (145 males and 195 females) were included in the study. The mean age was 47.7 ± 1.9 years. Of which, 93 patients (27.4%) were diagnosed with acute appendicitis with radiological/histological examination. Using cut‐off values of 5, the sensitivity of RIPASA, Alvarado & modified Alvarado scores were 75.3% (65.2%–83.6%), 67.7% (57.3%–77.1%) & 53.8% (43.1%–64.2%) respectively. While the specificity of RIPASA, Alvarado & modified Alvarado scores were 57.5% (51.1%–63.7%), 75.7% (69.9%–80.9%) & 85.8% (80.9%–89.9%) respectively. The corresponding accuracies were 60.0% (54.6%–65.2%), 74.6% (69.6%–79.1%) and 81.3% (76.8%–85.3%) respectively. Conclusion RIPASA score has higher sensitivity, but low specificity compared to Alvarado & modified Alvarado score. Since these scoring systems reveal different sensitivity and specificity parameters, it is still necessary to develop novel scores for risk stratification of patients with suspected acute appendicitis.