Report: Radiology among least common diagnostic errors
While diagnostic errors are encountered in every specialty and are generally lowest (less than five percent) for certain specialties that rely on visual pattern recognition and interpretation (e.g., radiology, pathology, dermatology), error rates in specialties that rely more on data gathering and the combination of different elements for a conclusive diagnosis are higher (10 to 15 percent), according to a September article published in the Pennsylvania Patient Safety Advisory.

“Errors related to missed or delayed diagnosis are frequently a cause of patient injury and therefore an underlying cause of patient safety related events,” wrote the authors of the autopsy analysis, which spanned several decades and showed error rates from four percent to 50 percent.

"Diagnostic errors are often the first or second leading cause of medical malpractice claims in the U.S.," said John Clarke, MD, clinical director of the Pennsylvania Patient Safety Authority. "They account for twice as many ongoing and settled claims as medication errors." He added that studies have also shown that both cognitive errors and system design flaws contribute to diagnostic error.

The Authority reviewed 100 events related to diagnostic error between June 2004 and November 2009 in an effort to determine if there were system solutions to diagnostic error, or if diagnostic error was so closely connected to doctors' cognitive processing that system solutions were not possible.

The researchers found reports in the Pennsylvania Patient Safety Reporting System, some of which revealed how advanced imaging techniques could avoid such diagnostic errors, including this example:
A young man came to the ED for fainting and syncope, including the inability to speak for a few seconds with lateralizing symptoms and staring. In the ED, lab work was done but no CT scan was ordered. Patient was discharged home with diagnosis of syncope and dehydration secondary to stress, with instructions to follow up with primary care physician. Subsequently, the primary care physician admitted the patient directly into the hospital, where a CT scan was performed and a brain lesion diagnosed.

The complete 2010 Pennsylvania Patient Safety Advisory can be found here.