The Increasing Use of Emergency Department Imaging in the United States: Is It Appropriate?

OBJECTIVE. The purpose of this study was to study trends in utilization of imaging in emergency departments (ED) in relation to trends in ED visits and the specialties of the interpreting physicians. MATERIALS AND METHODS. This study was conducted with Medicare Part B Physician/Supplier Procedure Summary Master Files for 2004-2016 and Health Care Cost and Utilization Project (HCUP) data from 2006 to 2014. Yearly utilization was calculated per 1000 Medicare beneficiaries for different noninvasive imaging modalities performed during ED visits, and the specialties of the physicians making the interpretations were recorded. The number of ED visits by Medicare patients was obtained from the HCUP. RESULTS. The number of ED visits by Medicare fee-for-service patients increased 8.0% (from 20.0 million in 2006 to 21.6 million in 2014), and the total number of associated ED imaging examinations increased 38.4% (14.6 million to 20.2 million). The number of imaging examinations per ED visit was 0.73 in 2006, increasing to 0.94 by 2014. Utilization trends per 1000 Medicare fee-for-service enrollees in the ED for the major modalities were as follows: CT + 153.0% (77.8 in 2004 to 196.7 in 2016), noncardiac ultrasound + 134% (11.2 in 2004 to 26.2 in 2016), and radiography + 30% (259 in 2004 to 336 in 2016). Utilization of MRI and nuclear medicine was very low. In 2016, radiologists interpreted 99.5% (CT), 99.2% (MRI), 98.0% (radiography), 87.6% (ultrasound), and 94.5% (nuclear medicine) of imaging examinations. CONCLUSION. Utilization of imaging in EDs is increasing not only in the Medicare population but also per ED visit. Radiologists strongly predominate in interpreting examinations in all modalities.