Doctors who are burned out from too much work and stress appear to have more racial biases that can affect the quality of care that their minority patients receive.

Researchers from the Mayo Clinic in Rochester and the University of Minnesota reached these findings by surveying more than 3,300 doctors during their on-the-job residency training.

Residents in their second years who reported more symptoms of burnout also tended to show more signs of explicit bias, meaning how they directly related to other people, and implicit bias, meaning the words they associated with other people based on their racial demographics.

While numerous studies have examined racial disparities in health care, and physician burnout, few had established a link between the two. Authors of the latest study, published online by the Journal of the American Medical Association, said the link is troubling but needed to be understood and now addressed.

"When physicians aren't operating in an optimal mental and emotional state, they may find it harder to push back against their own biases," said Dr. Liselotte Dyrbye, a lead author of the study and Mayo researcher who has created indexes to measure burnout levels in doctors and medical students. "If burnout contributes to disparities in care, perhaps fighting burnout can help narrow that gap."

The good news in the study was the appearance of a "dose dependent" relationship that worked both ways. While an increase in stress increased biases, the researchers found the greatest decline in biased attitudes in doctors who had overcome their burnout levels between their second and third years of residency.

The study, which included researchers from Oregon and Syracuse universities, focused on the biases against black people by surveying nonblack residents. Two-thirds of the surveyed doctors were white. Half were female.

Prior research has found that biases can affect the types of medical care that doctors order for patients. Stereotypes about the ability of people to handle complex orders, for example, might persuade doctors to refrain from recommending drugs with more complicated dosing regimens.

Biases also can result in doctors using more power-based or intimidating language, which can reduce patients' trust in them and compliance with their recommendations.

Minnesota Community Measurement, a nonprofit organization, has documented the impact by analyzing clinic and claims records. The organization found that clinics do a poorer job with minority patients in areas such as managing blood pressure and screening for cancer.

Jeremy Olson • 612-673-7744 • @stribjo