The Efficacy of the Alvarado Score in the Diagnosis of Acute Appendicitis

Purpose: Acute appendicitis is the most common cause of an acute abdomen that needs an emergency operation. However, the preoperative diagnosis is difficult. The purpose of this study is to assess the diagnostic efficacy of the Alvarado score by a comparison with CT and to determine the indication of CT evaluation. Methods: From August 2006 to October 2006, 111 consecutive patients were admitted to Chung-Ang University hospital under the impression of acute appendicitis, and a CT scan was done. The Alvarado score, which consists of migration, anorexia, nausea-vomitig, tenderness, rebound tenderness, fever, leukocytosis, and left shift, was applied to the patients. Results: Of the 111 patients, 85 patients underwent an operation, and 26 were discharged without an operation on the basis of the CT finding. The negative appendectomy rate were 4.7%. CT showed a sensitivity, of 0.90 a specificity of 0.97 and an accuracy rate of 0.92. Tenderness and leukocytosis were confirmed as the most important tests and showed accuracy rates of 0.73 and 0.70, respectively. The sensitivity was 0.90 at score 5 and 0.85 at score 7. Therefore, there was no single cut-off score that satisfied all diagnostic values. Conclusions: The Alvarado score alone is not a satisfactory diagnostic method acute appendicitis. Of the appendicitis patients, 90% might be included in the diagnosis for Alvarado scores above 5, and the negative appendectomy could be as high as 15% for Alvarado scores above 7, which is the score generally accepted for a diagnosis of appendicitis.