BRIEF REPORT
Availability and Quality of Computed Tomography and Magnetic Resonance Imaging Equipment in U.S. Emergency Departments Adit A. Ginde, MD, MPH, Anthony Foianini, BS, Daniel M. Renner, BE, Morgan Valley, MS, Carlos A. Camargo, Jr MD, DrPH
Abstract Objectives: The objective was to determine the availability and quality of computed tomography (CT) and magnetic resonance imaging (MRI) equipment in U.S. emergency departments (EDs). The authors hypothesized that smaller, rural EDs have less availability and lower-quality equipment. Methods: This was a random selection of 262 (5%) U.S. EDs from the 2005 National Emergency Department Inventories (NEDI)-USA (http://www.emnet-usa.org/). The authors telephoned radiology technicians about the presence of CT and MRI equipment, availability for ED imaging, and number of slices for the available CT scanners. The analysis was stratified by site characteristics. Results: The authors collected data from 260 institutions (99% response). In this random sample of EDs, the median annual patient visit volume was 19,872 (interquartile range = 6,788 to 35,757), 28% (95% confidence interval [CI] = 22% to 33%) were rural, and 27% (95% CI = 21% to 32%) participated in the Critical Access Hospital program. CT scanners were present in 249 (96%) institutions, and of these, 235 (94%) had 24 ⁄ 7 access for ED patients. CT scanner resolution varied: 28% had 1–4 slice, 33% had 5–16 slice, and 39% had a more than 16 slice. On-site MRI was available for 171 (66%) institutions, and mobile MRI for 53 (20%). Smaller, rural, and critical access hospitals had lower CT and MRI availability and less access to higher-resolution CT scanners. Conclusions: Although access to CT imaging was high (>90%), CT resolution and access to MRI were variable. Based on observed differences, the availability and quality of imaging equipment may vary by ED size and location. ACADEMIC EMERGENCY MEDICINE 2008; 15:780–783 ª 2008 by the Society for Academic Emergency Medicine Keywords: imaging, access to care, emergency medicine, rural, healthcare quality
T
he emergency department (ED) provides acute medical care 24 hours per day for an estimated 115 million patients in the United States each year.1 Characterization of the distribution and quality of emergency services has gained greater attention as public health officials have sought to understand and reduce From the Department of Emergency Medicine, University of Colorado Denver School of Medicine (AAG, AF, DMR, MV), Aurora, CO; and the Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School (CAC), Boston, MA. Received March 31, 2008; revision received May 13, 2008; accepted June 2, 2008. Presented at the Society for Academic Emergency Medicine Annual Meeting, Washington, DC, May 30, 2008. Address for correspondence and reprints: Adit A. Ginde, MD, MPH; e-mail:
[email protected].
780
ISSN 1069-6563 PII ISSN 1069-6563583
geographic disparities in access to high-quality emergency care. For instance, we recently created the first national inventory of U.S. EDs, a project that allowed us to describe the number, distribution, and basic characteristics of EDs.2 Increasingly, cross-sectional imaging has become an important component of the diagnostic evaluation for many ED patients. Indeed, ED utilization of computed tomography (CT) or magnetic resonance imaging (MRI) has increased from 2.4% of all ED visits in 1992 to 11.2% in 2005.1,3 National stroke and trauma guidelines recommend 24-hour availability of CT imaging and interpretation.4,5 Clinical pathways for abdominal pain and pulmonary embolism emphasize the role of CT in timely diagnosis.6,7 Additionally, multislice CT scanners have been touted for their increased quality and speed,8 but their availability for ED patients is unknown. Although not as widely utilized as CT, emergent MRI is
ª 2008 by the Society for Academic Emergency Medicine doi: 10.1111/j.1553-2712.2008.00192.x
ACAD EMERG MED • August 2008, Vol. 15, No. 8
•
www.aemj.org
increasingly utilized for stroke care and spinal emergencies and was performed during 0.5% of all U.S. ED visits in 2005.1 The availability and quality of diagnostic imaging equipment in U.S. EDs are important extensions of the effort to describe access to high-quality emergency care, but has not previously been characterized on a national level. In this study, we sought to characterize the availability and quality of CT and MRI equipment in U.S. EDs, with particular attention to differences based on ED characteristics. We hypothesized that smaller and rural EDs would have less availability of on-site cross-sectional imaging and less access to higherresolution equipment. METHODS Study Design and Population We performed a multicenter, cross-sectional survey of radiology technologists at a random sample of U.S. hospitals with EDs. We obtained Institutional Review Board approval with waiver of informed consent. We used the 2005 version of the National Emergency Department Inventories (NEDI)-USA (http://www. emnet-usa.org/nedi/nedi_usa.htm) to obtain a comprehensive list of all nonfederal US hospitals with EDs (n = 4,828). Methods for derivation of this database have been previously described.2 Briefly, NEDI-USA combines data from three sources: Verispan Marketing Group’s Hospital Market Profiling Solution Database, the American Hospital Association Annual Survey of Hospitals, and information collected independently by Emergency Medicine Network (Boston, MA) staff. EDs were defined as emergency care facilities that are open 24 hours per day, 7 days per week, and available for use by the general public; ‘‘urgent care’’ facilities known to be closed at certain hours or days were excluded. We obtained a random sample of 262 (5%) hospitals from the 2005 NEDI-USA database, using a random number generator. Site characteristics obtained from the database included: U.S. region, urban status, annual ED visit volume, critical access hospital status (receive federal reimbursement for importance in access to care in remote areas), and academic hospital status (per Association of American Medical Colleges Council of Teaching Hospital designation). Additionally, we used data from the Joint Commission (http:// www.jointcommission.org/) and the American College of Surgeons (http://www.facs.org/) to obtain site designations as primary stroke centers and trauma centers, respectively. Survey Content and Administration The survey asked whether the hospital had CT and MRI equipment available for imaging ED patients. Affirmative responses were recorded for ‘‘mobile’’ MRI units, if they were available for ED patients when on site. For hospitals with access to equipment, we asked about hours of availability for ED patients, including hours that technologists were at the hospital or on-call from home. Finally, we asked about the resolutions (in slices) of CT scanners.
781
Three study investigators (AF, DMR, MV) attempted to contact CT and MRI technologists by telephone during usual business hours. These investigators were unaware of the primary hypothesis at the time of data collection. If referred, responses from radiology department supervisors or physician radiologists were accepted. After verbal consent was obtained, we administered the
