Advanced radiologic imaging for pediatric appendicitis, 2005-2009: trends and outcomes.

OBJECTIVES: To examine the variability in the use of computed tomography (CT) and ultrasound (US) for children with appendicitis and identify associations with clinical outcomes, and to demonstrate any trends in diagnostic imaging between 2005 and 2009. STUDY
DESIGN: This was a retrospective review of children evaluated for appendicitis in an emergency department between 2005 and 2009 using an administrative database of 40 pediatric institutions in the United States. Imaging utilization by institutions was studied for association with 3 clinical outcomes.
RESULTS: A total of 55 238 children with appendicitis were studied. Utilization of CT and US varied widely across institutions, with medians of 34% (IQR, 21%-49%) for CT and 6% (IQR, 2%-26%) for US. Increased use of US or a combination of CT and US (but not of CT use alone) was associated with a lower negative appendectomy rate. Imaging was not associated with other clinical outcomes. In children with appendicitis, the use of US has increased since 2007, whereas that of CT has decreased.
CONCLUSION: There is considerable variation in the use of CT and US for children with appendicitis at major pediatric institutions. At the institutional level, increased use of US or combined US and CT is associated with a lower negative appendectomy rate. Despite the better diagnostic accuracy of CT compared with US, the use of CT is decreasing.