As an internist, working in the emergency room feels at times like the dark underbelly of medicine. The frenetic pace, the need to make decisions within highly uncertain conditions, and reliance on technology all cut against the grain of the internists credo of “being a doctor’s doctor.” If internists are biased in how they arrive at diagnoses, emergency medicine doctors face such bias on an exponential scale. Clinical decision-making is a tricky process, and so far no checklist or educational strategy has made it less tricky. Below are three strategies to further understand and demystify clinical bias.
1. Create a diagnostic batting average for physicians. Despite remarkable gains in information technology, we still have little data on comparative effectiveness of physicians. On a macro-level, quality metrics such as percentage of patients with diabetes or controlled hypertension capture the quality of healthcare systems, rather than individual clinicians. How then might we capture the difference in diagnostic accuracy amongst clinicians? I believe the emergency room is a good place to start. In a recent twelve-hour shift in the ED, I ordered three abdominal CT scans. Despite being assured in my diagnostic reasoning of gallbladder disease, pancreatitis, and diverticulitis, I wrong in 2/3 cases. Collecting this information is simple, and comparing it incredibly useful for understanding differences in diagnostic reasoning.
2. Foster and environment that combats testing momentum. Diagnostic momentum is tendency to continue with a diagnosis despite further information. A less-discussed bias is what I call “testing momentum,” the tendency to “test oneself to certainty.” I believe that this type of bias is more subtle and institutionalized. It can be heard in such statements as “he just bought himself a head CT” or “we need an abdominal CT to put his complaints to rest.” Part of this tendency is both practical and prudent; indeed, a negative abdominal CT scan will make everyone feel better sending the patient home (increased radiation exposure aside). But it also reflects a tunnel vision of care, in that had the patient presented for care in a different context, they would not have undergone as aggressive testing. As the problem is institutional, the solution may also be to continue to ask the question, “If the patient presented to the primary care clinic, what would you order?”
3. Push residents and students to defend testing choices. The recent push of the Choosing Wisely campaign will result in an extraordinary savings of inappropriate tests. The fact is, however, that the vast majority of tests ordered live in a gray zone of appropriateness. Does a person with a clear COPD exacerbation need a troponin test to measure for heart attack? Does a person with severe hypertension and vision changes need a CT scan? These gray zones represent the silent majority of clinical decision-making. In approaching them, we may do well to think of the concept of framing. Instead of asking, “What tests will you order?” we can ask, “Do we need to do any testing at all?” and finally, “What is the evidence behind your choice?”
The problem of cognitive bias in decision-making is both technical and cultural. To further understand it, we need to commit to collecting data differently, to actively question our decisions, and systematically explore the gray zones of medicine.
Tom Peteet is a board-certified internal medicine physician, educator, and writer. For nearly a decade, he has practiced at Commonwealth Care Alliance, focusing on home-based care for patients with complex disabilities. He also cares for patients in long-term care facilities and works with InstED, a mobile health program that brings acute care into patients’ homes.
As an adjunct professor at Massachusetts College of Pharmacy and Health Sciences, he directs a year-long pharmacology course for physician assistant students. At Boston University, he has taught more than ten courses through its prison education program and is developing courses in neuroscience and medical anthropology.
His scholarship spans medical ethics, medical education, and health equity, including work on the treatment rights of incarcerated patients, the role of theory and the humanities in medical training, and the intersection of quality improvement and equity in residency. His writing has appeared in the AMA Journal of Ethics, Medical Teacher, and the Journal of Family Medicine, and he authored a 2025 textbook chapter on renal disorders in Pathophysiology in Focus.
His writing explores health care ethics, medical education, and the overlooked paradoxes of human physiology. He writes Against Medical Advice, a Substack on the hidden science of medicine, and is working on a nonfiction book about the strange science of blood pressure. More of his work is available on his personal website.
