Author Affiliations: Department of Emergency Medicine, Brigham and Women's Hospital (Drs Raja, Andruchow, Zane, and Schuur); Center for Evidence-Based Imaging, Brigham and Women's Hospital (Drs Raja, Zane, and Khorasani); Department of Radiology, Brigham and Women's Hospital (Dr Khorasani); and Harvard Medical School, Boston, Massachusetts (Drs Raja, Zane, Khorasani, and Schuur).
Advanced diagnostic imaging use is increasing, raising concerns about patient safety and cost.1 Recent estimates indicate that 4000 future cancers may result from the head computed tomographic (CT) examinations performed nationwide in 20072 and that costs of CT and magnetic resonance imaging (MRI) doubled between 1997 and 2006.3 In US emergency departments (EDs), the greatest increase has been in neuroimaging (head CT and MRI).4 Nevertheless, there are no national benchmarks against which health care providers and hospitals can measure their use of ED neuroimaging. We aimed to calculate head CT and MRI use in US EDs and to examine patient and hospital factors associated with use.
We performed a cross-sectional analysis of neuroimaging in US EDs by analyzing the 2007 National Hospital Ambulatory Medical Care Survey (NHAMCS) ED component with a primary outcome of head CT use and a secondary outcome of head MRI use. We coded patient and hospital covariates a priori to identify predictors of neuroimaging and calculated the percentage of visits (with 95% confidence intervals [CIs]) associated with neuroimaging. We conducted multivariate logistic regression to estimate the adjusted association of covariates on the primary outcome. The regression model had good fit, with a C statistic of 0.71. Among visits in which head CT was performed, we calculated the leading reasons for visit5 and discharge diagnoses by grouping primary International Classification of Diseases, Ninth Revision, Clinical Modification discharge diagnoses into the 285 clinical categories of the Clinical Classification System.6 We performed all statistical analyses using SAS 9.1.3 (SAS Institute Inc, Cary, North Carolina).
There were approximately 117 million visits to 4891 US EDs in 2007, based on 35 490 ED visits in the NHAMCS sample. Head CT scans were performed during 6.7% (95% CI, 6.1%-7.3%) of visits, while head MRIs were performed during 0.26% (95% CI, 0.18%-0.35%) of visits. Patient and hospital characteristics associated with neuroimaging are presented in the Table. Patient characteristics independently associated with lower use of head CT use were decreasing age and non-Hispanic black race and ethnicity (vs non-Hispanic whites). Hospital characteristics associated with lower CT use included rural setting (vs urban) and hospitals owned by state or local governments (vs nonprofit hospitals).
The 3 leading reasons for visits among patients receiving head CTs in the ED were trauma (18.1%; 95% CI, 12.8%-23.5%), headache (13.0%; 95% CI, 10.8%-15.2%), and dizziness (6.1%, 95% CI, 4.6%-7.6%). The 3 leading discharge diagnosis categories were trauma (20.5%; 95% CI, 15.8%-25.3%), headache (9.2%; 95% CI, 7.4%-11.0%), and epilepsy/convulsions (5.2%; 95% CI, 3.8%-6.6%).
To our knowledge, this study provides the first nationally representative benchmarks of ED neuroimaging. In 2007, 1 in 14 ED patients received head CT, while 1 in 400 underwent head MRI. Increasing age was the strongest predictor of head CT use. While 1 in 34 children younger than 18 years received head CT, 1 in 7 patients 65 and older received one. Current guidelines addressing the use of ED head CT for trauma7 and acute headache8 exclude these older patients. Organizations interested in measuring and reducing neuroimaging will be challenged to define acceptable evidence-based appropriateness standards for older adults.
Use of head CT varied by race: 1 in 14 non-Hispanic white patients received head CT, compared with 1 in 19 non-Hispanic black patients. Yet it remains unclear whether this difference represents a quality disparity (ie, underuse) or an overuse disparity because the optimal rate of imaging is unknown and we could not assess appropriateness.
Large numbers of US ED patients are undergoing high-cost neuroimaging and receiving ionizing radiation with known cancer risks. Further research on appropriate indications for neuroimaging and implementation of performance improvement programs are needed to ensure that these valuable technologies are used in a safe and cost-effective manner.
Correspondence: Dr Raja, Department of Emergency Medicine, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115 (firstname.lastname@example.org).
Author Contributions:Study concept and design: Raja, Zane, Khorasani, and Schuur. Acquisition of data: Raja and Schuur. Analysis and interpretation of data: Raja, Andruchow, and Schuur. Drafting of the manuscript: Raja, Andruchow, and Zane. Critical revision of the manuscript for important intellectual content: Raja, Andruchow, Zane, Khorasani, and Schuur. Statistical analysis: Raja and Schuur. Administrative, technical, and material support: Raja, Zane, and Khorasani. Study supervision: Khorasani and Schuur.
Financial Disclosure: None reported.
Thank you for submitting a comment on this article. It will be reviewed by JAMA Internal Medicine editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 11
Customize your page view by dragging & repositioning the boxes below.
The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Make the Diagnosis: Does This Patient With Headaches Have a Migraine or Need Neuroimaging?
The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Original Article: Does This Patient With Headache Have a Migraine or Need Neuroimaging?
All results at
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.