On average, about 15 percent of a doctor’s diagnoses are inaccurate. Groopman directs a well-aimed arrow at a system of medical training that more often than not fails to investigate why these diagnoses are missed. Doctors are rarely taught to ask how an error could have taken place, let alone how it could be avoided in the future.

NYRB has a fine review of the book How Doctor’s Think by Jerome Groopman. Given our near blind-faith in doctors’ diagnoses, this cloud of doubt on the accuracy of such diagnoses is quite unsettling. The review highlights some of the cognitive biases that may lead to mis-diagnoses on the part of doctors, and provides a quick cheat-sheet like enlightenment based on parts of the book to the doctor and reader alike.

What I found particularly interesting, was the list of cognitive biases that may lead to incorrect diagnosis.

Patients might be stigmatized if they are thought to have a mental health problem, or caricatured if they are judged to have engaged in self-harming behavior, such as alcoholism. This kind of mistake is called “attribution error.” “Availability error” occurs when a doctor makes a decision based on an experience that is at the forefront of his mind but which bears little or no relation to the patient before him. “Search satisfying error” takes place when a doctor stops looking for an answer to the patient’s problem as soon as he discovers a finding that satisfies him, albeit incorrectly. “Confirmation bias” intrudes when the doctor selects only some parts of the information available to him in order to confirm his initial judgment of what is wrong. “Diagnostic momentum” takes over when the doctor is unable to change his mind about a diagnosis, even though there might remain considerable uncertainty about the nature of a patient’s condition. And “commission bias” obstructs good clinical thinking when the doctor prefers to do something rather than nothing, irrespective of clinical clues suggesting that he should sit on his hands.

When one thinks about it, these biases may as easily affect the way we reach an opinion in the course of our day-to-day interactions.Knowing and avoiding such and other biases may help us reach a clearer explanation for what we observe.

A list of cognitive biases can be found here.

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