Liberal use of computed tomography scanning does not improve diagnostic accuracy in appendicitis

Background: Based on a study at our hospital in 1994, we established a practice guideline for appendicitis patients. The practice guideline was followed well except for an increased number of preoperative computed tomography (CT) scans. Methods: Data collected from the previous study of 100 patients were compared with data from consecutive patients, 118 total, seen over a similar time period in the year 2000. Results: The percentage of CT scans ordered for the diagnosis of patients who underwent appendectomy markedly increased from 11% in 1994 to 48.3% in 2000. (P <0.001) The percentage of normal appendixes removed did not change significantly from 12% in 1994 to 17.8% in 2000 (P = 0.317). Patients who had a CT scan were no less likely to have a normal appendix at surgery (P = 0.386) and a significant increase in preoperative Emergency Department length of stay (P <0.001). CT was accurate 80% of the time in 2000 and 81% of the time in 1994. Only 14 of 57 CT scans were ordered by surgeons. Conclusions: The use of preoperative abdominal CT scanning has not improved the accuracy of the diagnosis of appendicitis at our institution. It has resulted in a significant increase in Emergency Department preoperative length of stay and the finding of a normal appendix at surgery. As nonsurgeons ordered the majority of preoperative CT scans, earlier input by surgeons might increase the rate of accurate clinical diagnosis and decrease the number of CT scans ordered.