One in 14 hospital patients may be the victim of damaging diagnostic mistakes, new research suggests.

The finding is from a study of 675 patients admitted to one large hospital in Boston at various periods between July 2019 and September 2021. The patients were randomly selected from more than 9,000 hospitalized during that time.

"The majority of [the diagnostic errors] were preventable," a team led by Dr. Anuj Dalal of Brigham and Women's Hospital in Boston concluded in the study published online Oct. 1 in the journal BMJ Quality & Safety. Dalal is also an instructor in internal medicine at Harvard Medical School.

With 85% of the errors deemed preventable, researchers said their findings underscore the need for improved surveillance to avoid mistakes in the first place.

The most frequent errors involved cases of heart and kidney failure, sepsis, pneumonia, respiratory failure, altered mental state, belly pain and low blood oxygen levels.

Harm was classified as minor, moderate, severe and fatal, and researchers assessed whether the diagnostic error was a contributor.

In all, they identified diagnostic errors in 160 cases involving 154 patients. Fifty-two owed to complex medical issues; 54 resulted in transfer to the intensive care unit; and 34 patients died within 90 days. 

Harmful errors occurred in 84 cases, resulting in  37 intensive care transfers and 18 deaths within 90 days, the study found. 

Patients at highest risk of a preventable error were older, white, non-Hispanic and those using public insurance.

Researchers emphasized that the findings were drawn from a single medical center, restricted to patients who had a stay under 21 days and relied on information from electronic health records, which may be inaccurate. Results should be interpreted with caution, they said in a journal news release.