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HPS Legal Alert: Recent Study Releases Emergency Department Misdiagnosis Statistics

By Kenneth J. Miller.

In December 2022, the Agency for Healthcare Research & Quality (the AHRQ) published new findings regarding diagnostic errors made when a patient is in an Emergency Department (ED). The AHRQ is one of twelve agencies within the United States Department of Health & Human Services. The AHRQ contracted with researchers from Johns Hopkins University to study decades of data relating to these errors. The AHRQ report is now available to the public. This alert will review some of the key findings.

How Frequent Are ED Errors?

There are approximately 130 million ED visits per year in the United States. The data obtained for the study revealed that 7.4 million patients were misdiagnosed, 2.6 million suffered an adverse event as a result of an error, and approximately 370,000 suffered serious harm from an error. Statistically speaking, the researchers concluded that while the ED error rates are low, the number of patients affected is high, and that improvement is certainly possible.

What Are the Top Conditions?

Only five conditions account for 39% of the more serious misdiagnosis-related harms:

  1. Stroke
  2. Myocardial infarction
  3. Aortic aneurism/dissection
  4. Spinal cord compression injury
  5. Venus thromboembolism

90% of most ED diagnostic errors that led to serious harm were linked to the cognitive challenge of identifying the underlying disorder. Which means the increase in the likelihood of a diagnostic error taking place increases in situations where the patient has presented nonspecific or atypical symptoms. For example, stroke victims are 40% more likely to be misdiagnosed when they present with nonspecific dizziness or vertigo symptoms.

Where Do They Occur?

The researchers found that error rates were usually found to be lower in academic or teaching hospitals vs. rural, federal or community hospitals, etc. This difference in error rates could be attributed to the increased availability or intensive use of diagnostic technologies or certain specialists being more readily available in the academic or teaching hospital environment.


There are some concerns about this study by organizations such as the American College of Emergency Physicians. But situations (like the disturbing increase in the number of patients kept waiting when hospitals cannot find beds) show that the results of the report are in line with the current state of affairs, and that there are real and systematic failures in EDs that the Federal Government needs to address.

If you are dealing with a situation involving a misdiagnosis in an ED, and you have questions, please contact Ken Miller, or any member of our Haliczer Pettis & Schwamm legal team.