Study: One in Three Severe Medical Malpractice Claims Stem from Diagnostic Errors

Diagnostic errors are a huge source of preventable medical malpractice injuries and claims every year. Estimates for the national number of diagnostic errors vary widely, with different studies estimating anywhere between 40,000 to four million diagnostic errors annually. Now, a new John Hopkins University School of Medicine study has revealed that over one in three medical malpractice claims that resulted in permanent injury or death over a 10-year period were caused by diagnostic errors.

The purpose of this study was to estimate the real burden of serious misdiagnosis-related harm in the U.S. Researchers analyzed nearly 55,000 closed medical malpractice claims from 2006 to 2015, finding that diagnostic errors are the most common, catastrophic, and costly type of medical error in the U.S. Lead author of the study, Dr. David Newman-Toker, commented on this finding, saying that “it’s not just inconvenient to have a wrong or delayed diagnosis. For many patients, misdiagnosis causes severe harm and expense, and in the worst cases, death.”

Researchers also found that nearly three in four serious misdiagnosis-related harms can be attributed to diseases in just three major categories: vascular events, infections, and cancers. Cancers accounted for more claims than the other two categories combined. For cancers, greater than 80 percent of the injuries or deaths were caused by poor clinician judgement.

In fact, failure in clinician judgement was by far the top contributing cause of serious misdiagnosis-related harms, indicating a need for solutions that support better decision-making in clinicians. Suggested solutions include technological, computer-based tools, automated image interpretation, and enhancements to diagnostic education and performance feedback.

It is also important to note that malpractice claims do not represent all diagnostic errors, meaning the true scale of the problem likely remains unknown. It has been estimated that only 1.5 percent of negligent medical care events result in malpractice claims, keeping the extent to which malpractice claims mirror harm caused in actual clinical practice unclear.

Ultimately, this research opens the door for future research to find a more accurate annual incidence rate, type of error, and frequency of errors. It could also serve as useful in finding ways to reduce poor physician judgement, which makes the life-or-death difference to millions of patients every year.