Door-In-Door-Out Process Times at Primary Stroke Centers in Chicago

Ann Emerg Med. 2021 Nov;78(5):674-681. doi: 10.1016/j.annemergmed.2021.06.018. Epub 2021 Sep 29.


Study objective: Acute stroke patients often require interfacility transfer from primary stroke centers to comprehensive stroke centers. Given the time-sensitive benefits of endovascular reperfusion, reducing door-in-door-out time at the primary stroke center is a target for quality improvement. We sought to identify modifiable predictors of door-in-door-out times at 3 Chicago-region primary stroke centers.

Methods: We performed a retrospective analysis of consecutive patients with acute stroke from February 1, 2018 to January 31, 2020 who required transfer from 1 of 3 primary stroke centers to 1 of 3 affiliated comprehensive stroke centers in the Chicago region. Stroke coordinators at each primary stroke center abstracted data on type of transport, medical interventions and treatments prior to transfer, and relevant time intervals from patient arrival to departure. We evaluated predictors of door-in-door-out time using median regression models.

Results: Of 191 total patients, 67.9% arrived by emergency medical services and 57.4% during off-hours. Telestroke was performed in 84.2%, 30.5% received alteplase, and 48.4% underwent a computed tomography (CT) angiography at the primary stroke center. The median door-in-door-out time was 148.5 (interquartile range 106 to 207.8) minutes. The largest contributors to door-in-door-out time, in minutes, were CT to CT angiography time (22 [7 to 73.5]), transfer center contact to ambulance request time (20 [8 to 53.3]), ambulance request to arrival time (20.5 [14 to 36]), and transfer ambulance time at primary stroke center (26 [21 to 35]). Factors associated with door-in-door-out time were (adjusted median differences, in minutes [95% confidence intervals]): CT angiography performed at primary stroke center (+39 [12.3 to 65.7]), walk-in arrival mode (+53 [4.1 to 101.9]), administration of intravenous alteplase (-29 [-31.3 to -26.7]), intubation at primary stroke center (+23 [7.3 to 38.7]), and ambulance request by primary stroke center (-20 [-34.3 to -5.7]).

Conclusion: Door-in-door-out times at Chicago-area primary stroke centers average nearly 150 minutes. Reducing time to CT angiography, receipt of alteplase, and ambulance request are likely important modifiable targets for interventions to decrease door-in-door-out times at primary stroke centers.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chicago
  • Emergency Medical Services / statistics & numerical data*
  • Fibrinolytic Agents / administration & dosage
  • Humans
  • Patient Transfer / statistics & numerical data*
  • Retrospective Studies
  • Stroke / diagnostic imaging*
  • Stroke / therapy*
  • Time Factors
  • Time-to-Treatment / statistics & numerical data*
  • Tissue Plasminogen Activator / administration & dosage*
  • Tomography, X-Ray Computed


  • Fibrinolytic Agents
  • Tissue Plasminogen Activator