Related Experiment Video
Updated: Mar 28, 2026
Setting Up a Stroke Team Algorithm and Conducting Simulation-based Training in the Emergency Department - A Practical Guide
Published on: January 15, 2017
Enrollment Yield and Reasons for Screen Failure in a Large Prehospital Stroke Trial
Dae-Hyun Kim1, Jeffrey L Saver2, Sidney Starkman1
1From the Department of Neurology, Busan-Ulsan Regional Cardiocerebrovascular Center, College of Medicine, Dong-A University, Busan, Republic of Korea (D.-H.K.); Departments of Neurology (J.L.S., D.S.L., L.K.A., L.R., M.V.-S.), Emergency Medicine and Neurology (S.S.), Comprehensive Stroke Center, and Department of Emergency Medicine, Los Angeles County Fire EMS Agency (F.P.), David Geffen School of Medicine, University of California, Los Angeles; Department of Neurology, Roxanna Todd Hodges Comprehensive Stroke Clinic (M.K.-T., N.S.) and Department of Emergency Medicine, Los Angeles Fire Department (M.E.), Keck School of Medicine, University of Southern California, Los Angeles; Department of Emergency Medicine, Los Angeles EMS Agency, Orange County EMS Agency, Harbor-University of California, Los Angeles Medical Center (S.S.); Stanford University, Palo Alto, CA (S.H.); and National Institute of Neurological Disorders and Stroke, Bethesda, MD (R.C.).
Background And Purpose:
The enrollment yield and reasons for screen failure in prehospital stroke trials have not been well delineated.
Methods:
The Field Administration of Stroke Therapy-Magnesium (FAST-MAG) trial identified patients for enrollment using a 2 stage screening process-paramedics in person followed by physician-investigators by cell phone. Outcomes of consecutive screening calls from paramedics to enrolling physician-investigators were prospectively recorded.
Results:
From 2005 to 2012, 4458 phone calls were made by paramedics to physician-investigators, an average of 1 call per vehicle every 135.7 days. A total of 1700 (38.1%) calls resulted in enrollments. The rate of enrollment of stroke mimics was 3.9%. Among the 2758 patients not enrolled, 3140 reasons for screen failure were documented. The most common reasons for nonenrollment were >2 hours from last known well (17.2%), having a prestroke condition causing disability (16.1%), and absence of a consent provider (9.5%). Novel barriers for phone informed consent specific to the prehospital setting were infrequent, but included: cell phone connection difficulties (3.2%), patient being hard of hearing (1.4%), insufficient time to complete consent (1.3%), or severely dysarthric (1.3%).
Conclusions:
In this large, multicenter prehospital trial, nearly 40% of every calls from the field to physician-investigators resulted in trial enrollments. The most common reasons for nonenrollment were out of window last known well time, prestroke confounding medical condition, and absence of a consent provider.
Clinical Trial Registration:
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059332.
