title: On- versus Off-Hour Patient Cohorts at a Primary Stroke Center: Onset-to-Treatment Duration and Clinical Outcomes after IV Thrombolysis.
abstract: BACKGROUND
  The symptom onset-to-treatment (OTT) duration predicts symptomatic intracerebral hemorrhage (sICH) and adverse outcomes after ischemic stroke. Previous studies found disparities in OTT durations and clinical outcomes between stroke patients with symptom onset during on-hours versus off-hours, which led to the initiation of nationwide efforts to provide consistent 24-hour stroke care.
  
  
  OBJECTIVE
  Our objective is to compare OTT durations and clinical outcomes in ischemic stroke patients whose symptoms originated during on- versus off-hours at a primary stroke center.
  
  
  METHODS
  We analyzed clinical data from 210 consecutive patients receiving intravenous recombinant tissue plasminogen activator therapy between January 2009 and December 2013 at Yale-New Haven Stroke Center, a primary stroke center. Stroke severity was assessed by baseline National Institutes of Health Stroke Scale (NIHSS) scores. Clinical outcomes were assessed by presence of sICH and by stroke-related fatalities. OTT durations and clinical outcomes were compared using Mann-Whitney tests, 2-sample tests of proportions, and 2-sample t-tests after testing for equal variance.
  
  
  RESULTS
  We found no significant differences in OTT durations between on-hour and off-hour patient cohorts (137 minutes versus 145 minutes, P = .53). There were also no differences in stroke severity (mean NIHSS score 12.4 versus 11.3, P = .27), sICH rates (4.6% versus 6.5%, P = .56), or stroke fatality rates (9.2% versus 9.8%, P = .89) between the 2 cohorts.
  
  
  CONCLUSIONS
  Our results represent progress in emergency response and acute stroke care, and reinforce ongoing nationwide efforts to increase stroke awareness and provide consistent quality care for patients with acute stroke.
authors.affiliation: Yale School of Medicine, New Haven, Connecticut.
authors.forename: David
authors.initials: D
authors.lastname: Asuzu
authors.affiliation: Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Karin
authors.initials: K
authors.lastname: Nystrӧm
authors.affiliation: Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Hardik
authors.initials: H
authors.lastname: Amin
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Joseph
authors.initials: J
authors.lastname: Schindler
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Charles
authors.initials: C
authors.lastname: Wira
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: David
authors.initials: D
authors.lastname: Greer
authors.affiliation: Department of Neurology, Taipei Medical University Hospital and Shuang Ho Hospital, Taipei, Taiwan.
authors.forename: Nai Fang
authors.initials: NF
authors.lastname: Chi
authors.affiliation: Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Janet
authors.initials: J
authors.lastname: Halliday
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Yale Department of Emergency Medicine, Division of Vascular Neurology, Division of Neurocritical Care and Emergency Neurology, Yale Department of Neurology, Yale-New Haven Hospital, New Haven, Connecticut. Electronic address: kevin.sheth@yale.edu.
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Sheth
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000188:drug therapy*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000188:drug therapy*; D015912:Thrombolytic Therapy; D013997:Time Factors; D061665:Time-to-Treatment; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: IV thrombolysis; Ischemic stroke; acute stroke care; onset to treatment