title: Imaging utilization from the ED: no difference between observation and admitted patients.
abstract: OBJECTIVE
  This study aims to determine the use of diagnostic imaging in emergency department (ED) observation units, particularly relative to inpatients admitted from the ED.
  
  
  METHODS
  Retrospective, descriptive analysis.
  
  
  METHODS
  Our database of ED patients was retrospectively reviewed to identify patients managed in the observation unit or admitted to inpatient services. In February 2014, we randomly selected 105 ED observation patients and 108 patients admitted to inpatient services from the ED. Electronic medical records were reviewed to assess diagnosis as well as type and quantity of imaging tests obtained.
  
  
  RESULTS
  Eighty (76%) ED observation patients underwent imaging tests (radiographs, 39%; computed tomography, 25%; magnetic resonance imaging (MRI), 24%; ultrasound, 8%; other, 4%); 85 inpatients (79%) underwent imaging tests while in the ED (radiographs, 52%; computed tomography, 30%; MRI, 8%; ultrasound, 9%; other, 1%). There was no significant difference in overall imaging use between ED observation patients and inpatients, but ED observation patients were more likely to undergo MRI (P=.0243). The most common presenting diagnoses to the ED observation unit were neurologic complaints (25%), abdominal pain (17%), and cardiac symptoms (16%).
  
  
  CONCLUSIONS
  There is no difference in the overall use of imaging in patients transferred to the ED observation unit vs those directly admitted from the ED. However, because ED observation unit patients tend to be accountable for a higher proportion of their health care bill, the impact of imaging in these patients is likely substantive.
authors.affiliation: Division of Cardiovascular Imaging and Emergency Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA. Electronic address: aprabhakar@partners.org.
authors.forename: Anand M
authors.initials: AM
authors.lastname: Prabhakar
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Misono
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: H Benjamin
authors.initials: HB
authors.lastname: Harvey
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Yun
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Saini
authors.affiliation: Division of Vascular Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Rahmi
authors.initials: R
authors.lastname: Oklu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003952:Diagnostic Imaging / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011859:Radiography / Q000706:statistics & numerical data; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D014463:Ultrasonography / Q000706:statistics & numerical data; D055815:Young Adult