Scoring system for computer-aided diagnosis of acute appendicitis. The value of prospective versus retrospective studies.

The high negative exploration rate in patients with suspected acute appendicitis is the main compelling reason to improve the accuracy in managing patients with acute abdominal pain. In this article, data from a prospective study on a group of patients undergoing an acute appendectomy were used to devise a scoring system for the purpose of differentiating between the patients with an acute appendicitis and those found to have a normal appendix at operation. The results show that by using the scoring system described, 30% of the unnecessary appendectomies could have been avoided. These findings show the potential value of this method. The results of the prospective study were compared with the results of a retrospective study on the same group of patients demonstrating a significant difference and hence the unreliability of retrospective studies.