Misdiagnosis contributes to nearly 800,000 serious injuries and deaths each year

Key points to remember:

• An expert has said that misdiagnoses of vascular and infection are more likely to lead to serious harm than misdiagnoses of cancer.
• The heavy burden of misdiagnosis warrants further efforts to improve diagnoses.

According to a study recently published in BMJ Quality and Safety.

“In 2015, the National Academy of Medicine stated in its report “Improving Diagnosis in Health Care” that improving diagnosis was a “moral, professional, and public health imperative,” but also noted that “available research [is] is not sufficient to extrapolate a specific estimate or range of the incidence of misdiagnosis in clinical practice today, David E. Newman-Toker, MD, PhD, a professor of neurology at John Hopkins Medicine, told Healio. “We sought a scientifically sound answer to the question of how many patients in the United States suffer serious harm as a result of medical misdiagnosis.”

Newman-Toker and colleagues performed a cross-sectional analysis using hospital discharge data from 2012 to 2014 to examine annual vascular and infectious events and US registry data from 2014 to examine annual new cancers. They then multiplied national disease estimates in each of the “big three” categories by the proportion of patients with that disease who were misdiagnosed or seriously harmed.

The researchers found that there are 6 million strokes, 6.2 million infections, and 1.5 million cancers each year in the United States. The weighted average rates of misdiagnosis and serious harm were 11.1% and 4.4%, respectively, per illness case.

The estimated annual number of serious damages was 795,000, but in a sensitivity analysis this figure was reduced to 549,000.

The top 15 diseases in each disease category accounted for 50.7% of all serious harm, while the top five diseases – sepsis, venomous thrombosis, stroke, lung cancer and pneumonia – accounted for 38.7%.

Although the researchers expected the annual number of severe harms to be high and weren’t surprised which diseases were often the culprits, “we were surprised to see that 15 diseases accounted for 50% of the severe harms and the five most frequently harmful ones accounted for nearly 40% of the severe harms,” ​​Newman-Toker said.

Newman-Toker and colleagues suggested that because of the lower number of diseases that contribute heavily to misdiagnosis and serious harm, “significant progress” could be made by tackling “just a few dangerous diseases that are relatively common.”

Newman-Toker added that malpractice claims in primary care are often missed cancer diagnoses; however, “missed vascular events and infections are more likely to result in serious patient harm.”

“This is due to the much higher frequency of vascular events (~6 million US cases per year) and infections (~6.2 million US cases per year) compared to cancers (~1.5 million US cases per year), with comparable misdiagnosis rates,” he said. “Cancers are likely overrepresented in malpractice claims because there is more opportunity over time to miss a diagnosis and there is often a ‘paper trail’ (eg, a missed lung nodule on a chest x-ray).”

Future research, Newman-Toker said, should view heart attack diagnoses in patients with chest pain as a “‘shining star’ example of what can be accomplished when we dedicate significant resources to solving the problem of misdiagnosis.”

“We found serious damage rates of less than 1% of heart attack cases,” he said. “Research needs to develop similar, multifaceted solutions for other diseases, such as stroke – we need a mix of teamwork, training, technology and tuning (feedback) to create multiple safety nets, then studies to demonstrate their impact in real-world practice. We need political action to increase research funding; new quality metrics and regulatory accountability for good diagnostic outcomes; and new payment models to incentivize payments accurate, timely and diagnoses communicated effectively.”