title: Value of computed tomography scans in ED dizziness visits: analysis from a nationally representative sample.
abstract: OBJECTIVE
  The study aimed to assess measures of the clinical value of computed tomography (CT) scans in dizziness presentations at the aggregate level.
  
  
  METHODS
  Using emergency department (ED) dizziness presentations captured in the National Hospital Ambulatory Medical Care Survey, the proportion of dizziness visits with a CT scan that received a central nervous system (CNS) diagnosis was measured yearly (1995-2004) and assessed for a trend over time. The independent association of having a CT scan with ED length of stay was examined using multivariable linear regression models.
  
  
  RESULTS
  The proportion of dizziness visits with a CT scan that received a CNS diagnosis dropped 62% from 1995 to 2004 (P < .05). By 2004, 94.1% (95% confidence interval, 89.4%-96.7%) of dizziness visits with a CT did not receive a CNS diagnosis. Having a CT scan was associated with a substantial increase in the length of stay with the effect modified by the number of other tests performed (range of increase, 40-77 minutes).
  
  
  CONCLUSIONS
  The clinical value of CT scans in dizziness presentations at the aggregate level may be very low and appears to have dropped over time. Computed tomography scans in the general dizziness population could also be an important contributor to ED length of stay. Use of CT scans in dizziness presentations should be a target for efforts to optimize the effectiveness and efficiency of care.
authors.affiliation: Department of Neurology, University of Michigan Health System, Ann Arbor, MI 48109, USA. kakerber@umich.edu
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Kerber
authors.forename: Lisa
authors.initials: L
authors.lastname: Schweigler
authors.forename: Brady T
authors.initials: BT
authors.lastname: West
authors.forename: A Mark
authors.initials: AM
authors.lastname: Fendrick
authors.forename: Lewis B
authors.initials: LB
authors.lastname: Morgenstern
mesh_terms: D004244:Dizziness / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology
references.citation: Acad Emerg Med. 2008 Aug;15(8):744-50
references.pmid: 18638027
references.citation: Mayo Clin Proc. 2007 Nov;82(11):1319-28
references.pmid: 17976351
references.citation: JAMA. 1999 Jul 7;282(1):36-9
references.pmid: 10404909
references.citation: Ann Neurol. 1986 Mar;19(3):291-3
references.pmid: 3963774
references.citation: Acad Emerg Med. 2007 Jan;14(1):63-8
references.pmid: 17200515
references.citation: JAMA. 1994 Mar 2;271(9):703-7
references.pmid: 8309035
references.citation: J Neurol Neurosurg Psychiatry. 2007 Jul;78(7):710-5
references.pmid: 17135456
references.citation: Emerg Med J. 2005 Apr;22(4):312
references.pmid: 15788853
references.citation: Lancet. 2007 Jan 27;369(9558):293-8
references.pmid: 17258669
references.citation: Neurology. 1996 Apr;46(4):942-8
references.pmid: 8780069
references.citation: Neurology. 2006 Oct 10;67(7):1178-83
references.pmid: 17030749
references.citation: Stroke. 2006 Oct;37(10):2484-7
references.pmid: 16946161
references.citation: Neurology. 2008 Jun 10;70(24 Pt 2):2378-85
references.pmid: 18541870
references.citation: BMC Fam Pract. 2005 Jan 06;6(1):2
references.pmid: 15636636
references.citation: N Engl J Med. 2003 Mar 13;348(11):1027-32
references.pmid: 12637613
references.citation: Am J Emerg Med. 2007 Jul;25(6):643-50
references.pmid: 17606089
references.citation: Lancet Neurol. 2008 Oct;7(10):951-64
references.pmid: 18848314
references.citation: Acad Emerg Med. 2008 Feb;15(2):177-82
references.pmid: 18275448
references.citation: Mayo Clin Proc. 2008 Jul;83(7):765-75
references.pmid: 18613993
references.citation: Am J Emerg Med. 1994 Jul;12(4):421-4
references.pmid: 7811322
references.citation: J Neurol Neurosurg Psychiatry. 2008 Apr;79(4):458-60
references.pmid: 18344397
references.citation: N Engl J Med. 1999 Nov 18;341(21):1590-6
references.pmid: 10564690