Reducing computed tomography scans for appendicitis by introduction of a standardized and validated ultrasonography report template.

Purpose: Computed tomography (CT) for the diagnosis of appendicitis is associated with radiation exposure and increased cost. In an effort to reduce the diagnostic use of CT scans, we implemented a standardized ultrasound report template based on validated secondary signs of appendicitis.

Methods: In September 2012, as part of a quality improvement project, we developed and introduced a four category standardized ultrasound report template for limited right lower quadrant abdominal ultrasounds. Outcomes for patients undergoing ultrasound or CT scan for appendicitis between 9/10/2012 and 12/31/2013 (Period 2, n=2033) were compared to the three months prior to implementation (Period 1, n=304).

Results: In Period 1, 78 of 304 (25.7%) patients had appendicitis versus 385 of 2033 (18.9%) in Period 2 (p=0.006). Non-diagnostic exams decreased from 48% to 0.1% (p<0.001). Ultrasound sensitivity improved from 66.67% to 92.2% (p<0.001). Specificity did not significantly change (96.9% to 97.69%, p=0.46). CT utilization for appendicitis decreased from 44.3% in Period 1 to 14.5% at the end of Period 2 (p<0.001).

Conclusions: Implementation of a standardized ultrasound report template based on validated secondary signs of appendicitis nearly eliminated non-diagnostic exams, improved diagnostic accuracy, and resulted in a striking decrease in CT utilization.