Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services (BEST-MSU Study), United States, 2014-2022 (ICPSR 39547)
Version Date: Aug 3, 2026 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
Jose-Miguel Yamal, University of Texas Health Science Center at Houston. School of Public Health;
James C. Grotta, Memorial Hermann-Texas Medical Center
https://doi.org/10.3886/ICPSR39547.v1
Version V1
Summary View help for Summary
The standard care of hospital or emergency department patients experiencing an acute ischemic stroke includes intravenously administered tissue plasminogen activator (tPA). Mobile stroke units (MSUs) are ambulances equipped with staff and a computed tomographic scanner that can allow for tPA to be administered more quickly. This comparative effectiveness trial examined clinical outcomes in stroke patients who received either an earlier diagnosis and treatment using an MSU or standard triage and transport by Emergency Medical Services (EMS). The sample included multicenter cohorts with randomized deployment weeks and blinded assessment of both trial entry and clinical outcomes.
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Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reason for the request, and obtain IRB approval or notice of exemption for their research.
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Study Purpose View help for Study Purpose
The primary goal of the Benefits of Stroke Treatment Delivered by a Mobile Stroke Unit Compared with Standard Management by Emergency Medical Services (BEST-MSU) trial was to compare pre-hospital diagnosis and treatment of patients with stroke symptoms using a Mobile Stroke Unit (MSU) with subsequent transfer to a Comprehensive Stroke Center (CSC) Emergency Department (ED) for further management to standard pre-hospital triage and transport by Emergency Medical Services to a CSC ED for evaluation and treatment (Standard Management). Specifically, the study aimed to:
- Compare the clinical outcome of patients meeting criteria for treatment on the MSU compared to Standard Management.
- Determine the agreement between the vascular neurologist (VN) on board the MSU with a VN remotely assessing a suspected stroke patient for treatment via telemedicine in the MSU, and the rate of technical failures in conducting the telemedicine consultation.
- Determine the incremental cost and effectiveness associated with the MSU compared to Standard Management using exploratory cost-effectiveness analyses.
Study Design View help for Study Design
Patient enrollment took place between August 2014 and August 2020 across seven U.S. cities. Some cities included multiple study sites. Eligible patients were assigned to the trial groups based on prospective designation of alternating weeks at each study site between Mobile Stroke Unit (MSU) or Standard Management Emergency Medical Services (EMS) treatments. The days of the week and timeframe of patient enrollment varied at each study site (e.g., 8 a.m. to 6 p.m. Monday through Saturday at one site; 8 a.m. to 5 p.m. Monday through Friday at four sites).
Local 911 dispatch centers identified and alerted MSU and EMS teams of patients experiencing a potential stroke within 4.5 hours after the onset of symptoms ("last seen normal"). On weeks assigned to MSU teams, the MSU, staffed by one or two paramedics, a CT technologist, a critical care nurse, and a vascular neurologist (either onsite or remotely through telemedicine), met an EMS team on the scene. The patient's history, blood glucose level, and neurologic and general physical condition were evaluated by both teams. The MSU team also performed the following steps before patients were transported to the emergency department:
- established intravenous access on the patient,
- determined the patient's National Institute of Health Stroke Scale (NIHSS) score,
- took a noncontrast CT of the patient's head,
- controlled for blood pressure, and
- started the tissue plasminogen activator (tPA) infusion (if eligible based on standard administration protocols).
On weeks assigned to the EMS team, an MSU nurse met the EMS team and patient at the emergency department. The EMS team shared patient history, glucose level, and neurologic and general physical exam findings with the MSU nurse. The NIHSS score was measured at the emergency department by the MSU nurse and adjusted as necessary based on information provided by the EMS team. Patient care, imaging, and tPA administration were managed by the emergency department hospital staff.
Patient quality of life information was collected quarterly for 12 months after the stroke. Cost and hospital utilization data were collected in person at baseline, discharge, and three months post-stroke; phone surveys were conducted at six, nine, and 12 months post-stroke.
Sample View help for Sample
The research team screened 10,443 emergency dispatches for strokes and enrolled 1,515 patients. Of these, 886 were enrolled to the MSU group and 629 to the Standard Management EMS group.
Time Method View help for Time Method
Universe View help for Universe
Patients experiencing acute ischemic stroke within 4.5 hours after the onset of symptoms.
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Description of Variables View help for Description of Variables
The data files in this collection are organized following the order of forms in the Data Collection Instruments documentation file. Data were collected on patient medical history, health assessment, medical and hospital resource utilization, adverse events, and various stroke event evaluations, vital signs, imaging, and treatment criteria. Patient demographics on gender, race and ethnicity, education, employment status, and income were also collected. Please see the questionnaire documentation for more information.
Presence of Common Scales View help for Presence of Common Scales
- Modified Rankin Scale
- National Institute of Health Stroke Scale (NIHSS)
Original Release Date View help for Original Release Date
2026-08-03
Version History View help for Version History
2026-08-03 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Created variable labels and/or value labels.
- Checked for undocumented or out-of-range codes.
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