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

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.

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).

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).

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.