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Study Led by HSR&D Investigator Suggests 12 Million Outpatients Misdiagnosed Annually

April 21, 2014

A study led by HSR&D investigator, Hardeep Singh, M.D., part of HSR&D's Center for Innovations in Quality, Effectiveness and Safety (IQuESt), analyzed three previous studies related to diagnosis and follow-up visits to determine the frequency of diagnostic errors among outpatients in the United States. Findings published in BMJ Quality & Safety show that about 12 million adults who seek outpatient medical care–or 1 out of 20 patients–are misdiagnosed. Moreover, it is estimated that in half of those cases, the misdiagnosis has the potential to cause severe harm. Dr. Singh and colleagues examined outpatient misdiagnosis rates from hundreds of medical records that were included in the three studies: one study of patients in a primary care setting, and two studies that included rates of misdiagnosis among lung cancer and colon cancer patients. Dr. Singh defined a misdiagnosis as "...a definite missed opportunity to make a timelier, correct diagnosis based on information available at that time."

Findings from this study, which was funded by the Agency for Healthcare Research and Quality (AHRQ), have been widely disseminated, including The Boston Globe and Reuters, as well as CBS News and NBC News.

In addition, a related article published in JAMA Internal Medicine (2013) authored by Dr. Singh and colleagues reported results of a study partly funded by HSR&D that examined potential predictors of missed test results in the setting of electronic health record (EHR)-based alerts. Findings showed that the median number of alerts reported by VA primary care physicians were 63 per day, and 87% of PCPs found this to be excessive. Also see Dr. Singh discuss missed and delayed diagnosis in a video on the HSR&D website, as it relates to follow-up test results and information overload for frontline providers.