Computed tomography associated cancers and cancer deaths following visits to U.S. emergency departments.

We estimated the number of future cancers and cancer deaths following computed tomography scans (CTs) performed in U.S. emergency departments annually and determined whether increases in the proportion of visits resulting in CTs over the past decade were accompanied by changes in markers of severity of illness or primary reason for visit. We applied national estimates of effective dose to adult emergency department visits in the 2008 National Hospital Ambulatory Medical Care Survey. We utilized the Biologic Effects of Ionizing Radiation Model VII to estimate the number of future cancers and cancer deaths caused by CTs performed in U.S. emergency departments. We calculated the proportion of visits resulting in CTs from 1998 to 2008. In 2008, 16,406,921 CTs were performed nationally on adults, which will cause an estimated 3,750 cancers and 1,994 cancer deaths. The increasing proportion of emergency department visits resulting in CTs was not accompanied by proportional increases in markers of severity of illness or primary reason for visit. The substantial number of future cancers and cancer deaths attributable to CTs and increases in CTs without accompanying increases in markers of severity or changes in primary reason for visit highlight the importance of examining the benefits of CTs.