title: Utilization of electroencephalogram post cardiac arrest in the United States: A nationwide retrospective cohort analysis.
abstract: The use of electroencephalogram (EEG) has been demonstrated to have diagnostic and prognostic value in cardiac arrest patients. The use of this modality across the United States in this population is unknown.
  
  
  
  The Nationwide Inpatient Sample (NIS) is a federal database capturing 20% of all US hospital admissions. A cohort of patients who suffered both in and out of hospital cardiac arrests from the 2006 to 2012 NIS datasets was created.
  
  
  
  The records of 55,208,382 hospitalizations were analyzed, of which 207,703 patients suffered a cardiac arrest. There were 2952 (1.42%) patients who also had an EEG. Patients who had an EEG compared to those who did not were: younger (62.2 years SD 16.6 vs 66.9 years SD 16.2, p<0.01), were less likely to have insurance coverage (89.9% vs 91.6%, p=0.03) and had significantly longer length of stay (8.6days IQR 3.7-17.1 vs 4.1days IQR 1.0-10.5, p<0.01). Patients treated at urban teaching hospitals were more likely to receive an EEG than patients treated at urban non-teaching and rural hospitals (p<0.01). The rate of EEG in survivors of cardiac arrest increased from 1.03% in 2006 to 2.16% in 2012, a relative increase of 110% (p<0.02). The median time to performance of an EEG was 1.6days IQR 0.33-4.53 days.
  
  
  
  EEG is performed on approximately 2% of patients who suffer cardiac arrest in the United States. The treatment hospital and patient characteristics of those who received an EEG different from those who did not.
authors.affiliation: Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, University of British Columbia, Room 2438, Jim Pattison Pavilion, 2nd Floor, 855 West 12th Avenue, Vancouver, BC V5Z 1M9, Canada; Harvard T.H. Chan School of Public Health, Harvard University, 677 Huntington Ave., Boston, MA 02115, USA. Electronic address: bar890@mail.harvard.edu.
authors.forename: Barret
authors.initials: B
authors.lastname: Rush
authors.affiliation: Division of Epilepsy, Department of Neurology, University of British Columbia, Vancouver, BC, Canada. Electronic address: ashkanani63@hotmail.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ashkanani
authors.affiliation: Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, University of British Columbia, Room 2438, Jim Pattison Pavilion, 2nd Floor, 855 West 12th Avenue, Vancouver, BC V5Z 1M9, Canada; Department of Anesthesia, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada. Electronic address: kaliromano@gmail.com.
authors.forename: Kali
authors.initials: K
authors.lastname: Romano
authors.affiliation: Division of General Internal Medicine, Department of Medicine, University Health Network, Toronto, Ontario, Canada. Electronic address: paul.hertz@uhn.ca.
authors.forename: Paul
authors.initials: P
authors.lastname: Hertz
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods / Q000706:statistics & numerical data; D015331:Cohort Studies; D016208:Databases, Factual; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data; D004632:Emergency Medical Services / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality / Q000628:therapy; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006780:Hospitals, Rural / Q000706:statistics & numerical data; D006786:Hospitals, Urban / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology
keywords: Cardiac arrest; Electroencephalogram; Prognostication; United States