Diagnostic errors are common in hospitals and are largely preventable, according to a new observational study led by Anuj K. Dalal, MD, from the Division of General Internal Medicine at Brigham and Women’s Hospital and Harvard Medical School in Boston, published in BMJ Quality & Safety.
Dalal and his colleagues found that 1 in 14 general medicine patients (7%) suffer harm due to diagnostic errors, and up to 85% of these cases could be prevented.
Few Studies on Diagnostic Errors
The study found that adverse event surveillance in hospital underestimated the prevalence of harmful diagnostic errors.
“It is difficult to quantify and characterize diagnostic errors, which have been studied less than medication errors,” Micaela La Regina, MD, an internist and head of the Clinical Governance and Risk Management Unit at ASL 5 in La Spezia, Italy, told Univadis Italy. “Generally, it is estimated that around 50% of diagnostic errors are preventable, but the authors of this study went beyond simply observing the hospital admission period and followed their sample for 90 days after discharge. Their findings will need to be verified in other studies, but they seem convincing.”
The researchers in Boston selected a random sample of 675 hospital patients from a total of 9147 eligible cases who received general medical care between July 2019 and September 2021, excluding the peak of the COVID-19 pandemic (April-December 2020). They retrospectively reviewed the patients’ electronic health records using a structured method to evaluate the diagnostic process for potential errors and then estimated the impact and severity of any harm.
Cases sampled were those featuring transfer to intensive care more than 24 hours after admission (100% of 130 cases), death within 90 days of hospital admission or after discharge (38.5% of 141 cases), complex clinical problems without transfer to intensive care or death within 90 days of admission (7% of 298 cases), and 2.4% of 106 cases without high-risk criteria.
Each case was reviewed by two experts trained in the use of diagnostic error evaluation and research taxonomy, modified for acute care. Harm was classified as mild, moderate, severe, or fatal. The review assessed whether diagnostic error contributed to the harm and whether it was preventable. Cases with discrepancies or uncertainties regarding the diagnostic error or its impact were further examined by an expert panel.
Most Frequent Situations
Among all the cases examined, diagnostic errors were identified in 160 instances in 154 patients. The most frequent situations with diagnostic errors involved transfer to intensive care (54 cases), death within 90 days (34 cases), and complex clinical problems (52 cases). Diagnostic errors causing harm were found in 84 cases (82 patients), of which 37 (28.5%) occurred in those transferred to intensive care; 18 (13%) among patients who died within 90 days; 23 (8%) among patients with complex clinical issues; and 6 (6%) in low-risk cases.
The severity of harm was categorized as minor in 5 cases (6%), moderate in 36 (43%), major in 25 (30%), and fatal in 18 cases (21.5%). Overall, the researchers estimated that the proportion of harmful, preventable diagnostic errors with serious harm in general medicine patients was slightly more than 7%, 6%, and 1%, respectively.