What is Your Blindspot: Managing Cognitive Bias

Taryn R Taylor MD, MEd

I can vividly remember my first day as a REAL doctor. I started on the pediatric pulmonology service, and recall spending what felt like an hour, deliberating whether I could order Tylenol for my patient. Would it interact with the Pulmozyme treatment? Fortunately, I had very patient senior resident who calmed my nerves and was empathetic to my intern anxiety.  July is an exciting, terrifying, rewarding and sometimes frustrating month, as we celebrate a new “medical year.” Whether or not you subscribe to the controversial premise of the July effect, there is no doubt that during this time you can leave a pivotal educational footprint in the life and career of a young doctor.

As we lead these learners on this educational journey, one of the most poignant lessons we can teach them is how to think critically. This includes recognizing and managing cognitive biases. Pattern recognition, which primarily occurs unconsciously, and analytical thinking which is deliberate and conscious, are the principle means by which we make medical decisions.  Cognitive biases are errors in reasoning that affect primarily the pattern recognition pathway. Debiasing strategies focus on transitioning from pattern recognition to a more analytic approach.1  By utilizing these debiasing strategies, we can reduce clinical errors committed by our learners and ourselves.

The first step in this process is to define and recognize the different type of cognitive errors that most commonly occur in medicine.

Anchoring: The patient’s chief complaint is sore throat, and they report an exposure to a family member with “strep.” This preliminary information seems quite convincing for a Group A beta-hemolytic streptococcal infection. However, upon further history gathering, the patient reveals symptoms of periodic heartburn, frequent belching and the sensation of food “getting stuck.”  Your learner, however, despite this additional information, is convinced that the patient should be treated immediately with antibiotics for the infectious process. This is an example of anchoring, during which one prematurely locks on to a diagnosis based on important preliminary information and fails to adjust this impression when additional information becomes available.

Information Bias: Innovative medical technology has afforded us the use of advanced radiologic imaging techniques and near instantaneous laboratory testing results. The utilization of such is not always efficient, affordable or practical. The tendency to believe that the more data one can collect to support a diagnosis the better, is called information bias.

Blind Spot Bias: As a seasoned, skilled physician, you have developed well defined illness scripts. You can recognize when a learner is going astray and are able to gently guide him or her back on track. Perhaps you do not recognize your own tendency towards gender bias or stereotyping. This is an example of blind spot bias: the ability to recognize the weakness or cognitive errors in others, and a tendency to overlook our own.

Over 100 different types of cognitive biases have been described in the literature. We are all vulnerable to these types of errors and being aware of them is a meaningful start to mitigating their effects. Wilson and Brekke 2 suggest an algorithmic approach to managing bias:

  • Become aware of the bias
  • Ensure that you and your learner are motivated to correct the bias
  • Recognize the magnitude of the bias
  • Apply an appropriate debiasing strategy

The authors suggest that successful completion of these steps lead to optimal decision making, however failure to complete these tasks leads to distortion of clinical reasoning. Dr. Croskerry 3,4 describes the following debiasing strategies.

  • Consider the alternatives: Routinely ask, “What else might this be?” Systematically generate and work through a differential diagnosis.
  • Metacognition: Metacognition is defined as the awareness and understanding of one’s own thought processes. Encourage learners to reflect on their approach to problem solving and self-critique, asking themselves what cognitive biases are at risk.
  • Decrease reliance on memory: One can improve the accuracy of judgments by using cognitive aids. These include mnemonics, clinical practice guidelines and algorithms, and the use of FOAM (Free Open Access to Meducation)
  • Feedback: Provide specific and timely feedback to decision makers so that errors are immediately appreciated, understood, and corrected.

Not all cognitive biases are created equally.  Likewise, the applicable strategies may differ, particularly considering the varying educational needs of young physician learners.  Taking an active approach to address cognitive bias is one step towards developing critical thinkers and decreasing medical error.


  1. Saposnik G, Redelmeier D, Ruff CC, Tobler PN. Cognitive biases associated with medical decisions: a systematic review. BMC Med Inform Decis Mak. 2016;16(1):1-14. doi:10.1186/s12911-016-0377-1.
  2. Wilson TD, Brekke N. Mental contamination and mental correction: Unwanted influences on judgments and evaluations. Psychol Bull. 1994;116(1):117-142. doi:10.1037/0033-2909.116.1.117.
  3. Croskerry P, Singhal G, Mamede S. Cognitive debiasing 1: Origins of bias and theory of debiasing. BMJ Qual Saf. 2013;22(SUPPL.2):1-7. doi:10.1136/bmjqs-2012-001712.
  4. Croskerry P. The importance of cognitive errors in diagnosis and strategies to minimize them. Acad Med. 2003;78(8):775-780. doi:10.1097/00001888-200308000-00003.

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