ROCHESTER, MN – Distress and fatigue among medical residents are contributing to self-perceived medical errors, according to Mayo Clinic researchers.

"We looked at distress and fatigue together and found that both factors can lead to a significant risk of medical error," says Colin West, MD, a Mayo Clinic physician and lead author of the study, which appears in the Journal of the American Medical Association. "Both fatigue and distress among medical residents represent a potential concern for patient safety."

Previous studies, including a 2006 JAMA article by the same authors, showed that burnout during the physician training process can lead to medical errors. Other studies have suggested resident fatigue also increases the risk of medical errors.

Mayo Clinic internal medicine residents were surveyed every three months from July 2003 to February 2009. Standardized survey tools were used to measure burnout, symptoms of depression, sleepiness and fatigue. At quarterly intervals, residents were also asked if they had made a major medical error in the last three months.

Of the 430 eligible residents, 88 percent answered at least one survey. Overall, 39 percent of the respondents reported at least one self-perceived major medical error during the study period.

"While changes have been made to reduce fatigue and sleepiness during residency training, other changes may be necessary to more specifically address distress and burnout," said Tait Shanafelt, MD, a Mayo physician and senior author.

The researchers said their findings might have implications beyond residency training and suggest that more attention to reducing non-fatigue-related distress among physicians may reduce errors and improve patient safety.

The authors said the findings are somewhat limited by study size, by the fact the study was conducted at only one institution, and because the survey tool used for symptoms of depression may not allow definitive diagnosis of that condition.