Systematic review: About one in 18 patients are misdiagnosed in ED

Approximately 7.4 million patients are misdiagnosed in EDs every year, according to a report from the HHS’ Agency for Healthcare Research and Quality.

“Diagnostic errors are a known patient safety concern across all clinical settings, including the ED,” David E. Newman-Toker, MD, PhD, director of the Armstrong Institute Center for Diagnostic Excellence at Johns Hopkins and president-elect of the Society to Improve Diagnosis in Medicine, and colleagues wrote. “We conducted a systematic review to determine the most frequent diseases and clinical presentations associated with diagnostic errors (and resulting harms) in the ED, measure error and harm frequency, as well as assess causal factors.”

The researchers searched Embase, PubMed and Cumulative Index to Nursing and Allied Health Literature from January 2000 through September 2021. They included targeted grey literature and research studies that reported misdiagnosis and related harms in EDs in the U.S. “or other developed countries with ED care deemed comparable,” they wrote.

Newman-Toker and colleagues then applied standard definitions for diagnostic errors, adverse events and serious harms like permanent disability or death, noting that “preventability was determined by original study authors or differences in harms across groups.”

Overall, the researchers identified 19,127 citations and included 279 studies in the systematic review.

Among 130 million ED visits in the U.S., 5.7% (95% CI, 4.4-7.1) of patients were misdiagnosed and 2% (95% CI, 1-3.6) — or 2.6 million people — suffered an adverse event as a result, the researchers found. Further, 0.3% — or 370,000 people — suffered potentially preventable permanent disability or death.

“This translates to about 1 in 18 ED patients receiving an incorrect diagnosis, 1 in 50 suffering an adverse event, and 1 in 350 suffering permanent disability or death,” Newman-Toker and colleagues wrote. “Put in terms of an average ED with 25,000 visits annually and average diagnostic performance, each year this would be over 1,400 diagnostic errors, 500 diagnostic adverse events and 75 serious harms, including 50 deaths per ED.”

Notably, “female sex and non-white race were often associated with important (20–30%) increases in misdiagnosis risk,” the researchers wrote.

About 68% of serious harms were attributable to just 15 diseases and were “linked to cognitive errors, particularly in cases with ‘atypical’ manifestations,” according to Newman-Toker and colleagues.

The top five conditions that were most commonly misdiagnosed — accounting for 39% of serious misdiagnosis-related harms — were:

• stroke;
• myocardial infarction;
• aortic aneurysm/dissection;
• spinal cord compression/injury; and
• venous thromboembolism.

The average disease-specific error rates, the researchers reported, varied from 1.5% (MI) to 56% (spinal abscess), “with additional variation by clinical presentation.” For example, the missed average was 17% for stroke but 4% for weakness and 40% for dizziness and vertigo. Additionally, there was variation by hospital; in one study, missed MI ranged from 0% to 29%.

“Although errors were often multifactorial, 89% of diagnostic error malpractice claims involved failures of clinical decision-making or judgment, regardless of the underlying disease present,” the researchers wrote. “Key process failures were errors in diagnostic assessment, test ordering, and test interpretation. Most often these were attributed to inadequate knowledge, skills, or reasoning, particularly in ‘atypical’ or otherwise subtle case presentations.”

Policy changes that should be considered in light of this review, according to the researchers, include:

• maximizing comparability of measures of misdiagnosis-related harms and diagnostic errors by standardizing measurement and research results reporting;
• tracking performance with a National Diagnostic Performance Dashboard; and
• facilitating the rapid development and implementation of solutions “to address this critically important patient safety concern” by using multiple policy levers like research funding, public accountability and payment reforms.

“Although estimated ED error rates are low ... the number of patients potentially impacted is large. Not all diagnostic errors or harms are preventable, but wide variability in diagnostic error rates across diseases, symptoms, and hospitals suggests improvement is possible,” the researchers concluded. “Scalable solutions to enhance bedside diagnostic processes are needed, and these should target the most commonly misdiagnosed clinical presentations of key diseases causing serious harms.”