Trends in advanced computed tomography use for injured patients in United States emergency departments: 2007-2010.

Abstract

Studies have documented increased advanced radiography use in U.S. emergency departments (EDs) for injured patients over the past decade. The authors explored trends in recent years (2007 through 2010) in advanced radiography use, specifically head computed tomography (CT) and nonhead CT scans. This was a retrospective analysis of ED visits conducted using data from the National Hospital Ambulatory Medical Care Survey (NHAMCS), a representative sample of the U.S. ED visits from 2007 through 2010. All patients designated by the NHAMCS as "related to injury" were included in analyses. CT use was examined by head and nonhead use. Trends, predictors of utilization, and diagnostic yield for head and nonhead CT scans in injured ED patients were analyzed using survey-weighted logistic regression. Diagnostic yield was defined as the proportion of injury-related visits where patients imaged with CT received International Classification of Diseases, 9th Revision (ICD-9), code diagnoses of a severe head or nonhead injury. Among injured ED patients, head CT use increased from 9.6% in 2007 to 11.6%, a relative increase of 20.8% (p<0.001), and nonhead CT from 5.5% to 7.3%, a relative increase of 47.3% (p<0.001). Diagnostic yield for head CT was unchanged (4.9% in 2007 vs. 3.4% in 2010, p=0.093), but fell for nonhead CT from 6.4% in 2007 to 3.3% in 2010 (p=0.04. Advanced radiography use has continued to increase since 2007 in injured patients, and diagnostic yield for nonhead CT has continued to fall. Head CT is more common than CTs of other body areas and may represent an opportunity for reduction given validated clinical decision rules.