The Armstrong Institute Center for Diagnostic Excellence

A growing body of evidence shows that diagnostic errors are the most common, catastrophic and costly of all medical errors. They are difficult to identify and often go unrecognized until it is too late. The science of diagnostic safety and quality remains underdeveloped and underfunded.

The center, which is the first of its kind in the world, provides a unique, collaborative, transdisciplinary environment for clinicians, researchers, engineers and data experts to work together to tackle the challenges of medical misdiagnosis. The Armstrong Institute Center for Diagnostic Excellence was borne out of a need to address this dangerous and costly problem. Housed in the Armstrong Institute and led by Dr. David Newman-Toker, a world leader in diagnostic error research, the center plans to eliminate preventable patient harms from diagnostic errors.

The Impact of Diagnostic Errors

Diagnostic errors will likely touch each of us in our lifetimes.

  • An estimated 12 million Americans are affected each year, and perhaps one-third are harmed as a result.
  • These errors may account for 40,000 to 80,000 preventable deaths annually in U.S. hospitals.

Though appropriate use of diagnostic tests can help combat diagnostic errors and add value to patient-centered care, more testing alone will not deliver diagnostic value. The costs of advanced diagnostic tests are spiraling upward faster than any sector of the health care industry, and inappropriate overuse of diagnostic tests will only multiply the costs. Diagnostic error and diagnostic test overuse are global problems requiring bold, innovative solutions.

Eighth Annual Diagnostic Excellence Summit: Measuring Diagnostic Excellence – from Data to Implementation

The 2024 Johns Hopkins Armstrong Institute Center for Diagnostic Excellence Summit will focus on measuring diagnostic excellence. This event is a pivotal gathering for health care professionals and researchers eager to delve into the significance of timely, accurate and well-communicated diagnosis.

Center Initiatives

The center’s first signature initiative will be to tackle stroke misdiagnosis throughout Johns Hopkins Hospital emergency departments. Future initiatives will address sepsis and cancer diagnosis. Together, the initiatives will address the “big three” that account for at least one-third of all diagnostic errors and likely more than half of the harms from diagnostic errors.

Why Stroke Misdiagnosis?

  • More than 1 million people in the United States suffer a stroke or transient ischemic attack (TIA, or pre-stroke) every year, with about three in four being first-time strokes.
  • Stroke is the fifth leading cause of death in the United States, killing nearly 130,000 people a year, or one every 4 minutes. That’s one in every 20 deaths.
  • Stroke is a leading cause of long-term disability and among the most preventable. Rapid access to treatment reduces brain injury, prevents complications, avoids major stroke after minor stroke and improves patient outcomes.
  • Minor, early strokes are currently missed 30 to 50 percent of the time, often when patients have common symptoms — dizziness, vertigo, headaches — that are diagnosed as a less serious problem.
  • Timely diagnosis leading to prompt, correct treatments can prevent death and disability.

Currently, a lack of prompt treatment leads to preventable harms because patients suffer major strokes after undiagnosed minor strokes. Our target is to cut harms from missed strokes in half within five years.

Our Multi-pronged Implementation Approach


We will train providers in the latest bedside diagnostic techniques using state-of-the art educational simulations. These will include screen-based case simulations for cognitive skills as well as novel partial task trainers for psychomotor skills. Our simulations will be driven by real-world data from our ongoing AVERT clinical trial (Clinical NCT02483429).

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We will launch the Comprehensive Unit-based Safety Program to Improve Diagnosis (CUSPID). This adapted version of the highly successful culture change framework known as CUSP will specifically target achieving diagnostic excellence through local, grass-roots efforts that identify diagnostic error problems, determine causes and envision solutions.

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We will apply cutting edge technologies to enhance early stroke recognition in the Johns Hopkins Health System’s emergency departments. Portable diagnostic devices will facilitate the use of telemedicine to deliver immediate expertise to the bedside. Automation of this process, currently underway in our AVERT clinical trial (Clinical NCT02483429), will further enhance accuracy and efficiency. These projects will increase quality and decrease costs.

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We will develop operational measures of diagnostic accuracy, error and value for stroke. Our first-generation Diagnostic Performance Dashboard will monitor harms from missed stroke and process failures, enabling feedback to providers and ensuring accountability at all levels. We will conduct economic analyses of stroke interventions, identifying the highest value solutions.

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Featured Research

Newly-released AHRQ Effective Healthcare Program report authored by the Johns Hopkins University Evidence-based Practice Center and experts at the Johns Hopkins Armstrong Institute Center for Diagnostic Excellence synthesizes 20 years of medical research, providing critical new insights into the frequency, distribution, and causes of diagnostic error and associated harms in the emergency department. 

Get Involved

Fellowship Opportunities

The Johns Hopkins University and the Society to Improve Diagnosis in Medicine is seeking candidates for the Fellowship in Diagnostic Excellence. Application due mid to late February, 2023.

Contact: Paul Bergl, [email protected]

Collaboration Opportunities

Want to join a core group? Interested in becoming a partner? Have ideas for new initiatives? Contact us at [email protected].

For those interested in a potential research partnership, please navigate to the research engagement interest form.

Annual Diagnostic Excellence Summit

The Annual Diagnostic Excellence Summit features expert speakers and small group discussions focused on ways to envision keeping diagnosis human in the digital age.

See past summits.

Medical Misdiagnosis: More Common Than You Think

Dr. David Newman-Toker discusses the impact of medical misdiagnoses on this podcast.

Support The Center for Diagnostic Excellence


To make a gift or pledge online, please complete our secure online giving form

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Over the Phone

To speak with someone directly about making a gift, please call 443-287-7949.

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Send via Mail

Mail your tax deductible contribution to:

Fund for Johns Hopkins Medicine
Armstrong Institute Center for
Diagnostic Excellence
550 North Broadway / Suite 701B
Baltimore, MD 21205

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Contact the Development Office

Armstrong Institute Center for Diagnostic Excellence
Fund for Johns Hopkins Medicine

If you have any questions, please contact us at
443-287-7949 or [email protected].

550 North Broadway
Suite 701B
Baltimore, MD 21205

News and Publications

The Armstrong Institute Center for Diagnostic Excellence provides resources for patients, providers, scientists and administrators working together to tackle the challenges of misdiagnosis. Regularly featured in national media, the following is a collection of the outlets where faculty and staff members help advance public knowledge on ways to address the problem of diagnostic errors.

Contact Us