Sensitivity and specificity of the Alvarado Score for the timely differential diagnosis of acute appendicitis for a case series in Samoa

BACKGROUND: Timely diagnosis of acute appendicitis (AA) is essential for optimal management of abdominal pain emergency presentations. Improved diagnostic procedures should minimise progression to complicated appendicitis, as well as reduce the number of unwanted surgical interventions. The Alvarado Score is an important tool to assist with the management of AA based on clinically predictive values. The aim of the present study was to evaluate the sensitivity and specificity of the Alvarado Score as an instrument for the diagnosis of AA in our low-resourced context of Samoa. MATERIALS AND METHODS: The lead investigator performed a retrospective clinical data review design of all patients admitted to the Tupua Tamasese Meaole Hospital Surgical Unit for AA from January 2015 to December 2016. Exclusion criteria were appendiceal abscess and/or mass, and final diagnosis ‘not acute appendicitis’. Age, sex, village, Alvarado Score, Ultrasound Scan Result, surgical management, and histopathology result were the main variables entered into the SPSS statistical software package for analysis. RESULTS: Of the 225 patients (2–86 years) admitted for AA, 67.1% (N = 151) underwent appendicectomy, and the remaining 32.9% (N = 74) were treated with antibiotics. An Alvarado Score (≥5) showed 91.7% sensitivity and 50% specificity for AA. There was a significant relationship between the Alvarado Score and the Ultrasound Scan for AA (p < 0.05). Histology results showed complicated AA in 68.6% (N = 94) of cases. The negative appendicectomy rate was 2.6%. CONCLUSIONS: The Alvarado Score is an effective tool for the timely differential diagnosis of AA in our Samoan context. The high rate of complicated acute appendicitis warrants investigation to further improve the management of AA in the Pacific Island setting.