How to Prevent Medical Diagnostic Errors

Learn How You Think

The human mind uses rules of thumb that help it to make decisions or quickly slice through an overwhelming amount of input. These shortcuts can also lead to certain types of mistakes—what psychiatry calls “cognitive biases.”

Pat Croskerry, MD, PhD, of Dalhousie University in Halifax, Nova Scotia, has written and lectured on cognitive-related factors in medical decision making. He described the two ways we make decisions: intuitive and rational. Intuitive decision-making is fast and compelling—it is the snap judgment or the gut instinct. Rational decision-making is slower and more deliberate.

While intuitive decision-making often serves physicians well, it is occasionally catastrophic. By virtue of its very speed and certainty, it can blind a physician to considering alternative explanations for a particular patient’s presentation. It’s important to understand that everyone relies on intuitive decision making, that it’s part of human nature, and that you must recognize it in order to overcome it.

What are cognitive biases? Here are some key biases that take place in a physician’s exam room:

• Anchoring bias. “That’s when you latch on to the first thing you see,” said David Eibling, MD, a professor of otolaryngology at the University of Pittsburgh Medical Center. By focusing on the most obvious symptom or the most likely diagnosis, a physician may fail to take into account conflicting information.
• Confirmation bias. Once a physician has a diagnosis in mind, he or she will seek confirming evidence. “But they may forget to look for refuting evidence,” Dr. Eibling said.
• Availability bias. That’s when a physician relies on recent experience, such as, “I’ve seen four of these cases this month; this must be number five.” By the same token, physicians may miss diseases they haven’t seen for awhile.

Dr. Eibling said it’s worth learning about cognitive biases because it allows you step back and see how you think, then determine where that thinking might lead you astray. Also, he said, it’s reassuring for many physicians to learn that these mistakes are encoded into how our brains work.

“Everybody gets uncomfortable when you start talking about errors,” Dr. Graber said. “But everybody gets interested when you show them the patterns of human error.” For example, you put your car keys down on the kitchen counter instead of in the bowl near the mail and then you can’t find them. Everyone recognizes that scenario, Dr. Graber said. “The silly cognitive mistakes we make in our everyday lives are the same ones that can lead to diagnostic errors.’”