title: Trends in Transcranial Doppler Monitoring in Aneurysmal Subarachnoid Hemorrhage: A 10-Year Analysis of the Nationwide Inpatient Sample.
abstract: BACKGROUND
  Transcranial Doppler (TCD) is endorsed by national guidelines for use in aneurysmal subarachnoid hemorrhage (aSAH) for surveillance of cerebral vasospasm (CV). However, nationwide data on utilization of TCD for CV detection and monitoring in aSAH are lacking.
  
  
  METHODS
  Analysis of nationwide trends in TCD prevalence was performed using Nationwide Inpatient Sample (NIS) data from 2002 to 2011. Raw counts were converted into weighted counts, which were used to generate national estimates. Teaching hospitals were examined separately for TCD utilization rates. All analyses accounted for the complex sampling design and sample discharge weights of the NIS, following Healthcare Cost and Utilization Project-NIS recommendations. The objective was to estimate the proportion of patients with aSAH receiving TCD monitoring using the NIS.
  
  
  RESULTS
  Between 2002 and 2011, a total of 256,089 patients were discharged with a diagnosis of aSAH, of which 3850 underwent TCD monitoring. aSAH accounted for an average of 67.1 discharges per 100,000 annually (95% confidence interval [CI] 61.3-72.8). Of these, 1.5% (95% CI 0.4-2.6) underwent TCD examination. In teaching hospitals, aSAH accounted for an average of 108.5 discharges per 100,000 biennially (95% CI, 96.2-120.8), of which 2% (95% CI 1.0-4.0) underwent TCD examination. TCD utilization increased from <1% during the 2002-2005 period to ≥1.5% during the 2006-2011 period (odds ratio 2.3, 95% CI 1.0-5.7), an increase also seen in teaching hospitals.
  
  
  CONCLUSIONS
  TCD is underused nationally in the care of aSAH. Whereas the prevalence of TCD is low in teaching hospitals, it is nearly nonexistent in nonteaching hospitals.
authors.affiliation: Department of Neurology, Mayo Clinic, Phoenix, Arizona. Electronic address: kumar.gyanendra@mayo.edu.
authors.forename: Gyanendra
authors.initials: G
authors.lastname: Kumar
authors.affiliation: Department of Neurology, Comprehensive Stroke Center, University of Alabama at Birmingham, Birmingham, Alabama; Geriatric Research, Education and Clinical Center (GRECC), Birmingham VA Medical Center, Birmingham, Alabama.
authors.forename: Karen C
authors.initials: KC
authors.lastname: Albright
authors.affiliation: Center for Outcome and Effectiveness Research and Education (COERE), University of Alabama at Birmingham, Birmingham, Alabama; Department of Preventive Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: John P
authors.initials: JP
authors.lastname: Donnelly
authors.affiliation: Department of Neurology, Comprehensive Stroke Center, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Angela Hays
authors.initials: AH
authors.lastname: Shapshak
authors.affiliation: Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Harrigan
mesh_terms: D005260:Female; D006801:Humans; D007297:Inpatients; D008137:Longitudinal Studies; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods* / Q000639:trends*; D014481:United States; D020301:Vasospasm, Intracranial
keywords: Aneurysmal subarachnoid hemorrhage; Nationwide Inpatient Sample; cerebral vasospasm; transcranial Doppler