Crafting Measures to Improve Accuracy of Stroke Diagnosis

“I think that 10 years from now, we will look back and say that AHRQ funded a study which made a huge difference to the entire field of diagnostic safety, quality, and excellence.”

A neurologist who has made timely and accurate diagnosis of patients with acute dizziness part of his core research mission, AHRQ grantee David Newman-Toker, M.D., Ph.D., remarks that he didn’t pick the symptom as a field of study, but that it picked him, because of its public health importance.

That’s because dizziness is “a common symptom that’s commonly misdiagnosed and occasionally—but not rarely—is due to something very serious,” he said. The estimated 18 million U.S. medical visits for dizziness each year include nearly 5 million emergency department (ED) visits, with more than one million patients likely to have a serious underlying cause.

Stroke is the most common of those serious causes, affecting approximately 4 percent of ED patients who seek medical attention for dizziness (spatial disorientation) or vertigo (a false sense of motion) each year, according to Dr. Newman-Toker, a Professor of Neurology, Ophthalmology and Otolaryngology at Johns Hopkins University (JHU), Baltimore, Maryland. He also holds joint appointments in Emergency Medicine and Health Sciences Informatics at JHU’s School of Medicine and directs the Johns Hopkins Armstrong Institute Center for Diagnostic Excellence.

Patients who come to hospital EDs with weakness on one side of the body are typically evaluated quickly and treated promptly for stroke, which requires rapid medical attention to prevent brain damage and other complications. But stroke patients who manifest dizziness have a 14-fold risk of being misdiagnosed, according to Dr. Newman-Toker, leading to delayed treatments and poor outcomes.

“We can’t afford to do advanced brain imaging on all 5 million ED patients with dizziness, but we also can’t afford not to do it in the nearly 200,000 who do have stroke as the cause. That means we need major, coordinated efforts to tackle this as a public health issue,” he noted.

Even when stroke is the underlying cause, ED clinicians are generally unaware that they’ve missed or misdiagnosed a stroke when a patient presents with dizziness. Instead, they label the symptom “benign” or diagnose an inner ear (balance) disorder. “Zero feedback makes it impossible for a physician to get better at their job,” Dr. Newman-Toker said.

His determination to reduce harms from misdiagnosis and improve ED clinicians’ diagnostic skills led to his current AHRQ grant, which will create a performance measure to assess hospitals’ track records on accurate stroke diagnosis. When this project is complete, the resulting measure will be used to assess the impact of multi-pronged solutions to address acute dizziness and stroke.

The stroke diagnosis measure is the fourth pillar of a four-pronged attack on ED stroke misdiagnosis that Dr. Newman-Toker refers to as the “four T’s”: teamwork, training, technology, and tuning. The first three pillars focus on solutions, but the fourth, tuning, refers to measurements that provide feedback on diagnostic performance before and after solutions are implemented.

Intended for eventual use in public reporting and accountability, the measure is being developed in collaboration with the American College of Emergency Physicians (ACEP) and the Society to Improve Diagnosis in Medicine (SIDM). Adding momentum to this effort, the National Quality Forum (NQF) has identified stroke misdiagnosis as a high-priority gap in need of a quality measure. Getting buy-in from ACEP and SIDM on the project was important, Dr. Newman-Toker said, “because engagement of trusted stakeholders is what it's going to take for hospitals and clinicians to want to adopt and use a measure like this.”

Now in its second of four years, the project to develop the stroke diagnosis measure is well on its way. Dr. Newman-Toker’s team has developed a draft measure specification, vetted it with a panel of experts, demonstrated performance variability across nearly 1,000 U.S. EDs using Medicare data, and submitted the draft for endorsement by the NQF as a national quality metric. He believes this measure will define a clearer path forward for other similar measures for diseases such as heart attack and sepsis, also under development by the JHU team.

A pioneer in the emerging field of diagnostic safety and quality, Dr. Newman-Toker received his first AHRQ grant in 2008, which focused on developing a clinical decision support tool to more accurately and efficiently capture a patient’s history of dizziness symptoms with a goal of preventing ED misdiagnosis. This work later became the cornerstone of data collection for the subsequent NIH-funded AVERT trial of a decision support-based diagnostic pathway of care for acute dizziness and vertigo, expected to conclude by 2022.

During the course of Dr. Newman-Toker’s investigations, awareness of the public health relevance of diagnostic error continued to grow. He received an AHRQ grant to support the Diagnostic Error in Medicine Conferences in 2010, 2011, and 2012, drawing diverse national and international audiences. The funding was “pivotal in the founding of the improving diagnosis movement,” he recalled. It allowed interested researchers and clinicians to meet, collaborate, and begin to craft a research and clinical quality improvement agenda. It also led to the 2011 formation of SIDM.

“The AHRQ conference grant enabled us to have the extra bandwidth and capability and people around us to launch the Society to Improve Diagnosis in Medicine, which is now a driving force in the field,” he said.

Dr. Newman-Toker has received multiple awards for his research, teaching, and leadership, and was named one of 125 “Hopkins Heroes” who personify the Johns Hopkins Medicine mission. He has served as an expert on diagnostic safety and quality for the NQF, the National Academy of Medicine, and the U.S. Congress. He is also a Past President of SIDM, and a current member of the American Academy of Neurology, the American Neurological Association, the North American Neuro-Ophthalmology Society, and the Bárány Society.

Principal Investigator: David E. Newman-Toker, M.D., Ph.D.
Institution: Johns Hopkins University, Baltimore
Grantee Since: 2008
Type of Grant: Various

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