Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final. In the meantime, results have been published in peer-reviewed journals, as listed below.

What is the research about?

A stroke happens when blood flow doesn’t reach the brain. Strokes can cause serious disability or death. But if strokes are treated quickly, patients may have a better recovery.

Getting patients to the hospital to test for a stroke can take time. In this study, the research team is comparing two ways to test for and treat stroke. One way is in the hospital as usual. The other way is to use mobile stroke units, which are ambulances that have special equipment and health care providers who can diagnose and treat stroke on the spot.

Who can this research help?

Directors of hospitals, fire departments, and emergency medical services can use results from this research when considering how to improve care for stroke.

What is the research team doing?

In Houston, Denver, and Memphis, the research team is setting up mobile stroke units. These ambulances carry a CT scanner and lab equipment that can help diagnose strokes. A stroke team with a neurologist, nurse, CT technician, and emergency medical technician ride in the ambulance. When someone calls 911 about a possible stroke, the stroke team goes to the patient.

First, the stroke team assesses whether the patient might be having a stroke. If a stroke seems likely, the stroke team evaluates the patient with the CT scanner and other tests. The neurologist sends the CT images to the hospital for later use. The stroke team provides treatment right away for patients who have had a stroke and takes all patients to the hospital for care.

During the study, the stroke team is responding to about 6,000 possible strokes across the three cities. The team is alternating providing either mobile stroke service or regular emergency care for people with possible stroke week-by-week until the middle of 2019.

Three months after patients in the study get treatment, the research team is following up to see how a stroke affected each patient’s health.

Emergency medical service providers and companies that make equipment to diagnose stroke are working with the research team to design the ambulances and plan the study. The research team is working with patients who have had a stroke to identify what treatment results to measure.

Research methods at a glance

Design Elements Description
Design Observational: cohort study
Population Adults ages 18 years and older with suspected stroke
  • Treatment via mobile stroke unit
  • Treatment in emergency department

Primary: utility-weight modified Rankin Scale, healthcare utilization, quality of life

Secondary: modified Rankin Scale, time from symptom onset to tPA treatment, symptomatic intracranial hemorrhage, mortality, stroke mimics

Timeframe Timeframe Length of follow-up for collecting data on primary outcomes. View Glossary 90-day follow-up for primary outcomes

Project Information

James Grotta, MD
Memorial Hermann Health System, Memorial Hermann-Texas Medical Center
BEnefits of Stroke Treatment Delivered Using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services: The BEST-MSU Study

Key Dates

July 2016
August 2023

Study Registration Information


Has Results
Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
Research Priority Area
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: January 20, 2023