Nearly 800,000 Americans die or are permanently disabled due to medical misdiagnoses, according to a new analysis published in BMJ Quality & Safety [1].

Experts with the Johns Hopkins Armstrong Institute Center for Diagnostic Excellence calculated the figure using data representative of the entire U.S. population. The investigation covered all care settings, including hospitals and clinics.

In particular, five conditions—lung cancer, stroke, sepsis, pneumonia and venous thromboembolism—caused the most frequent serious harm, accounting for 38.7% of the total.

“A disease-focused approach to diagnostic error prevention and mitigation has the potential to significantly reduce these harms,” neurologist David Newman-Toker, MD, PhD, lead investigator and director of the Center for Diagnostic Excellence, said in an announcement. “Reducing diagnostic errors by 50% for stroke, sepsis, pneumonia, pulmonary embolism and lung cancer could cut permanent disabilities and deaths by 150,000 per year.”  

To reach their conclusions, scientists with Johns Hopkins and Harvard performed a cross-sectional analysis of a nationally representative sample. This included 21.4 million hospital discharges from 2012 to 2014, used to estimate the yearly incidence of vascular events and infections, while new cancers were derived from 2014 U.S. registries. Newman-Toker et al. calculated rates for 15 major vascular events, infections and cancers, using incidence rates from medical literature and extrapolating totals across the U.S. population.

This resulted in final figures of 6 million vascular events, 6.2 million infections and 1.5 million cancers. Across these “Big Three” categories, there was an average “serious harm” rate of 4.4% and average diagnostic error rate of 11.1%. The authors estimated that about 795,000 diagnostic errors occur each year, with a “plausible range” of 598,000 to 1,023,000. The top 15 most dangerous disease accounted for nearly 51% of total serious harms, the authors noted, while the Big Three accounted for 75%.

Missed stroke cases were pinpointed as the top cause of serious harms. Johns Hopkins has already adopted several solutions to address this concern, including algorithms to automate parts of the diagnostic process.

“Funding for these efforts remains a barrier,” Newman-Toker said in the announcement. “Diagnostic errors are, by a wide margin, the most under resourced public health crisis we face, yet research funding only recently reached the $20 million per year mark. If we are to achieve diagnostic excellence and the goal of zero preventable harm from diagnostic error, we must continue to invest in efforts to achieve success.”  

Read more in the journal of the British Medical Association at the link below.